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  1. Impaired in vitro accumulation of mercury in erythrocytes of acatalasemic mice.

    OpenAIRE

    Yamamoto, Hideki; Ishii, Kunihiko; Meguro, Tadamichi; Taketa,Kazuhisa; Ogata,Masana

    1992-01-01

    In order to elucidate the role of erythrocyte catalase in the accumulation of mercury in erythrocytes, labeled erythrocytes and plasma were prepared by exposing normal and acatalasemic mice to radioactive mercury vapor (203Hg0: 6.8mg/m3) for 30 min. Labeled erythrocytes (or plasma) were mixed with unlabeled plasma (or erythrocytes) of normal or acatalasemic mice and incubated at 0 degrees C for 1 h. After incubation, the radioactivity of mercury in the erythrocytes and the plasma was measured...

  2. Acid Sphingomyelinase Inhibition Prevents Hemolysis During Erythrocyte Storage

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    Richard S. Hoehn

    2016-06-01

    Full Text Available Background/Aims: During storage, units of human red blood cells (pRBCs experience membrane destabilization and hemolysis which may cause harm to transfusion recipients. This study investigates whether inhibition of acid sphingomyelinase could stabilize erythrocyte membranes and prevent hemolysis during storage. Methods: Human and murine pRBCs were stored under standard blood banking conditions with and without the addition of amitriptyline, a known acid sphingomyelinase inhibitor. Hemoglobin was measured with an electronic hematology analyzer and flow cytometry was used to measure erythrocyte size, complexity, phosphatidylserine externalization, and band 3 protein expression. Results: Cell-free hemoglobin, a marker of hemolysis, increased during pRBC storage. Amitriptyline treatment decreased hemolysis in a dose-dependent manner. Standard pRBC storage led to loss of erythrocyte size and membrane complexity, increased phosphatidylserine externalization, and decreased band 3 protein integrity as determined by flow cytometry. Each of these changes was reduced by treatment with amitriptyline. Transfusion of amitriptyline-treated pRBCs resulted in decreased circulating free hemoglobin. Conclusion: Erythrocyte storage is associated with changes in cell size, complexity, membrane molecular composition, and increased hemolysis. Acid sphingomyelinase inhibition reduced these changes in a dose-dependent manner. Our data suggest a novel mechanism to attenuate the harmful effects after transfusion of aged blood products.

  3. Acute exercise induced oxidative stress is prevented in erythrocytes of male long distance athletes

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    A Gunal

    2008-06-01

    Full Text Available The aim of this study was to investigate the redox status in blood of long distance running athletes if it is favourably affected, and help to prevent acute exercise-induced oxidative stress. Nineteen sedentary males and 20 male long distance runners, volunteered to participate in this study. Acute exercise was applied as treadmill run, which was continued until the heart rate of the subject has reached 80-90% of the maximum and stopped after 5 min. Acute exercise increased the hematocrit percentage in sedentary males but not in male athletes. It decreased the number of erythrocytes and also Hb level in sedentary males, but not in male athletes when they were adjusted to the changes in hematocrit level. There was no difference in erythrocyte malondialdehyde levels between sedentary males and male athletes at rest. Acute treadmill run increased the erythrocyte malondialdehyde level in sedentary males, however, it did not affect it in male athletes. Erythrocyte glutathione peroxidase and superoxide dismutase activities were not affected by acute exercise in both groups. Our results show that erythrocytes in long distance male athletes are better protected against acute exercise-induced oxidative stress compared with the ones from sedentary counterparts.

  4. Towards functional antibody-based vaccines to prevent pre-erythrocytic malaria infection.

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    Sack, Brandon; Kappe, Stefan H I; Sather, D Noah

    2017-05-01

    An effective malaria vaccine would be considered a milestone of modern medicine, yet has so far eluded research and development efforts. This can be attributed to the extreme complexity of the malaria parasites, presenting with a multi-stage life cycle, high genome complexity and the parasite's sophisticated immune evasion measures, particularly antigenic variation during pathogenic blood stage infection. However, the pre-erythrocytic (PE) early infection forms of the parasite exhibit relatively invariant proteomes, and are attractive vaccine targets as they offer multiple points of immune system attack. Areas covered: We cover the current state of and roadblocks to the development of an effective, antibody-based PE vaccine, including current vaccine candidates, limited biological knowledge, genetic heterogeneity, parasite complexity, and suboptimal preclinical models as well as the power of early stage clinical models. Expert commentary: PE vaccines will need to elicit broad and durable immunity to prevent infection. This could be achievable if recent innovations in studying the parasites' infection biology, rational vaccine selection and design as well as adjuvant formulation are combined in a synergistic and multipronged approach. Improved preclinical assays as well as the iterative testing of vaccine candidates in controlled human malaria infection trials will further accelerate this effort.

  5. Associations of Erythrocyte Fatty Acids in the De Novo Lipogenesis Pathway with Proxies of Liver Fat Accumulation in the EPIC-Potsdam Study.

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    Jacobs, Simone; Jäger, Susanne; Jansen, Eugene; Peter, Andreas; Stefan, Norbert; Boeing, Heiner; Schulze, Matthias B; Kröger, Janine

    2015-01-01

    Biomarker fatty acids (FAs) reflecting de novo lipogenesis (DNL) are strongly linked to the risk of cardiometabolic diseases. Liver fat accumulation could mediate this relation. There is very limited data from human population-based studies that have examined this relation. The aim of this study was to investigate the relation between specific FAs in the DNL pathway and liver fat accumulation in a large population-based study. We conducted a cross-sectional analysis of a subsample (n = 1,562) of the EPIC-Potsdam study, which involves 27,548 middle-aged men and women. Baseline blood samples have been analyzed for proportions of 32 FAs in erythrocyte membranes (determined by gas chromatography) and biomarker concentrations in plasma. As indicators for DNL, the DNL-index (16:0 / 18:2n-6) and proportions of individual blood FAs in the DNL pathway were used. Plasma parameters associated with liver fat content (fetuin-A, ALT, and GGT) and the algorithm-based fatty liver index (FLI) were used to reflect liver fat accumulation. The DNL-index tended to be positively associated with the FLI and was positively associated with GGT activity in men (p for trend: 0.12 and 0.003). Proportions of 14:0 and 16:0 in erythrocytes were positively associated with fetuin-A, whereas 16:1n-7 were positively associated with the FLI and GGT activity (all p for trends in both sexes at least 0.004). Furthermore, the proportion of 16:1n-7 was positively related to fetuin-A in women and ALT activity in men (all p for trend at least 0.03). The proportion of 16:1n-9 showed positive associations with the FLI and GGT activity in men and fetuin-A in both sexes, whereas 18:1n-7 was positively associated with GGT activity in men (all p for trend at least 0.048). Findings from this large epidemiological study suggest that liver fat accumulation could link erythrocyte FAs in the DNL pathway to the risk of cardiometabolic diseases.

  6. Breast cancer risk accumulation starts early – Prevention must also

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    Colditz, Graham A; Bohlke, Kari; Berkey, Catherine S.

    2014-01-01

    Purpose Nearly 1 in 4 breast cancers is diagnosed before the age of 50, and many early-stage premalignant lesions are present but not yet diagnosed. Therefore, we review evidence to support the strategy that breast cancer prevention efforts must begin early in life. Methods Literature review Results Exposures during childhood and adolescence affect a woman’s long-term risk of breast cancer, but have received far less research attention than exposures that occur later in life. Breast tissue undergoes rapid cellular proliferation between menarche and first full-term pregnancy, and risk accumulates rapidly until the terminal differentiation that accompanies first pregnancy. Evidence on childhood diet and growth in height, and adolescent alcohol intake, among other adolescent factors are related to breast cancer risk and risk of premalignant proliferative benign lesions. Conclusion Breast cancer prevention efforts will have the greatest effect when initiated at an early age and continued over a lifetime. Gaps in knowledge are identified and deserve increase attention to inform prevention. PMID:24820413

  7. 4-Pyridone-3-carboxamide-1-β-D-ribonucleoside triphosphate (4PyTP), a novel NAD metabolite accumulating in erythrocytes of uremic children: a biomarker for a toxic NAD analogue in other tissues?

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    Synesiou, Elena; Fairbanks, Lynnette D; Simmonds, H Anne; Slominska, Ewa M; Smolenski, Ryszard T; Carrey, Elizabeth A

    2011-06-01

    We have identified a novel nucleotide, 4-pyridone 3/5-carboxamide ribonucleoside triphosphate (4PyTP), which accumulates in human erythrocytes during renal failure. Using plasma and erythrocyte extracts obtained from children with chronic renal failure we show that the concentration of 4PyTP is increased, as well as other soluble NAD(+) metabolites (nicotinamide, N(1)-methylnicotinamide and 4Py-riboside) and the major nicotinamide metabolite N(1)-methyl-2-pyridone-5-carboxamide (2PY), with increasing degrees of renal failure. We noted that 2PY concentration was highest in the plasma of haemodialysis patients, while 4PyTP was highest in erythrocytes of children undergoing peritoneal dialysis: its concentration correlated closely with 4Py-riboside, an authentic precursor of 4PyTP, in the plasma. In the dialysis patients, GTP concentration was elevated: similar accumulation was noted previously, as a paradoxical effect in erythrocytes during treatment with immunosuppressants such as ribavirin and mycophenolate mofetil, which deplete GTP through inhibition of IMP dehydrogenase in nucleated cells such as lymphocytes. We predict that 4Py-riboside and 4Py-nucleotides bind to this enzyme and alter its activity. The enzymes that regenerate NAD(+) from nicotinamide riboside also convert the drugs tiazofurin and benzamide riboside into NAD(+) analogues that inhibit IMP dehydrogenase more effectively than the related ribosides: we therefore propose that the accumulation of 4PyTP in erythrocytes during renal failure is a marker for the accumulation of a related toxic NAD(+) analogue that inhibits IMP dehydrogenase in other cells.

  8. 4-Pyridone-3-carboxamide-1-β-d-ribonucleoside Triphosphate (4PyTP, a Novel NAD+ Metabolite Accumulating in Erythrocytes of Uremic Children: A Biomarker for a Toxic NAD+ Analogue in Other Tissues?

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    Elizabeth A. Carrey

    2011-06-01

    Full Text Available We have identified a novel nucleotide, 4-pyridone 3/5-carboxamide ribonucleoside triphosphate (4PyTP, which accumulates in human erythrocytes during renal failure. Using plasma and erythrocyte extracts obtained from children with chronic renal failure we show that the concentration of 4PyTP is increased, as well as other soluble NAD+ metabolites (nicotinamide, N1-methylnicotinamide and 4Py-riboside and the major nicotinamide metabolite N1-methyl-2-pyridone-5-carboxamide (2PY, with increasing degrees of renal failure. We noted that 2PY concentration was highest in the plasma of haemodialysis patients, while 4PyTP was highest in erythrocytes of children undergoing peritoneal dialysis: its concentration correlated closely with 4Py-riboside, an authentic precursor of 4PyTP, in the plasma. In the dialysis patients, GTP concentration was elevated: similar accumulation was noted previously, as a paradoxical effect in erythrocytes during treatment with immunosuppressants such as ribavirin and mycophenolate mofetil, which deplete GTP through inhibition of IMP dehydrogenase in nucleated cells such as lymphocytes. We predict that 4Py-riboside and 4Py-nucleotides bind to this enzyme and alter its activity. The enzymes that regenerate NAD+ from nicotinamide riboside also convert the drugs tiazofurin and benzamide riboside into NAD+ analogues that inhibit IMP dehydrogenase more effectively than the related ribosides: we therefore propose that the accumulation of 4PyTP in erythrocytes during renal failure is a marker for the accumulation of a related toxic NAD+ analogue that inhibits IMP dehydrogenase in other cells.

  9. Prevention of calcium-induced membrane structural alterations in erythrocyte membranes by flunarizine

    NARCIS (Netherlands)

    Thomas, Peter G.; Zimmermann, A.G.; Verkleij, A.J.

    1988-01-01

    The calcium antagonist flunarizine is shown to be able to prevent particle aggregation, membrane aggregation and blebbing resulting from elevated calcium concentrations. The anti-ischemic effects of flunarizine may therefore result in part from its ability to directly interfere with calcium-membrane

  10. Thymoquinone, the Nigella sativa Bioactive Compound, Prevents Circulatory Oxidative Stress Caused by 1,2-Dimethylhydrazine in Erythrocyte during Colon Postinitiation Carcinogenesis

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    Hanene Jrah Harzallah

    2012-01-01

    Rats exposed to DMH showed an increase of malondialdehyde and conjugated diene levels, and an augmentation of enzyme activities like catalase, glutathione peroxidase, and superoxide dismutase activities was also noted. The TQ pretreatment restored the parameters cited above to near-normal values. However, the posttreatment shows an activity similar as that presented by DMH. Therefore, our investigation revealed that TQ was a useful compound preventing DMH-induced erythrocyte damages.

  11. Acute exercise induced oxidative stress is prevented in erythrocytes of male long distance athletes

    OpenAIRE

    A Gunal; F Akcay; Gul, M.; S Taysi; Dane, S.

    2008-01-01

    The aim of this study was to investigate the redox status in blood of long distance running athletes if it is favourably affected, and help to prevent acute exercise-induced oxidative stress. Nineteen sedentary males and 20 male long distance runners, volunteered to participate in this study. Acute exercise was applied as treadmill run, which was continued until the heart rate of the subject has reached 80-90% of the maximum and stopped after 5 min. Acute exercise increased the hematocrit per...

  12. Dietary indicaxanthin from cactus pear (Opuntia ficus-indica L. Mill) fruit prevents eryptosis induced by oxysterols in a hypercholesterolaemia-relevant proportion and adhesion of human erythrocytes to endothelial cell layers.

    Science.gov (United States)

    Tesoriere, Luisa; Attanzio, Alessandro; Allegra, Mario; Livrea, Maria A

    2015-08-14

    Toxic oxysterols in a hypercholesterolaemia-relevant proportion cause suicidal death of human erythrocytes or eryptosis. This process proceeds through early production of reactive oxygen species (ROS), release of prostaglandin (PGE2) and opening of PGE2-dependent Ca channels, membrane phosphatidylserine (PS) externalisation, and cell shrinkage. The present study was the first to reveal that a bioavailable phytochemical, indicaxanthin (Ind) from cactus pear fruit, in a concentration range (1.0-5.0 μM) consistent with its plasma level after a fruit meal, prevents PS externalisation and cell shrinkage in a dose-dependent manner when incubated with isolated healthy human erythrocytes exposed to an oxysterol mixture for 48 h. Dietary Ind inhibited ROS production, glutathione (GSH) depletion, PGE2 release and Ca2+ entry. Ind alone did not modify the erythrocyte redox environment or affect other parameters. Ex vivo spiking of normal human blood with the oxysterol mixture for 48 h induced eryptosis, resulting in the production of ROS and decreased levels of GSH, which was prevented by concurrent exposure to 5 μm-Ind. The adherence of eryptotic erythrocytes to the endothelium causes vascular tissue injury. Erythrocytes isolated from blood incubated with the oxysterol mixture plus 5 μm-Ind did not adhere to endothelial cell monolayers. Eryptotic erythrocytes may contribute to thrombotic complications in hypercholesterolaemia. Our findings suggest the positive effects of diets containing Ind on erythrocytes in hypercholesterolaemic subjects.

  13. Measuring a critical stress for continuous prevention of marine biofouling accumulation with aeration.

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    Menesses, Mark; Belden, Jesse; Dickenson, Natasha; Bird, James

    2017-10-01

    When cleaning the hull of a ship, significant shear stresses are needed to remove established biofouling organisms. Given that there exists a link between the amount of time that fouling accumulates and the stress required to remove it, it is not surprising that more frequent grooming requires less shear stress. Yet, it is unclear if there is a minimum stress needed to prevent the growth of macrofouling in the limit of continuous grooming. This manuscript shows that single bubble stream aeration provides continuous grooming and prevents biofouling accumulation in regions where the average wall stress exceeds ~0.01 Pa. This value was found by comparing observations of biofouling growth from field studies with complementary laboratory measurements that probe the associated flow fields. These results suggest that aeration and other continuous grooming systems must exceed a wall stress of 0.01 Pa to prevent macrofouling accumulation.

  14. Erythrocyte deformability and erythrocyte aggregation in preeclampsia

    NARCIS (Netherlands)

    Pepple, D. J.; Hardeman, M. R.; Mullings, A. M.; Reid, H. L.

    2001-01-01

    One of the features of preeclampsia is impaired blood rheology due to altered erythrocyte aggregation and erythrocyte deformability. We investigated these two parameters which affect the viscosity of blood, along with serum and intraerythrocytic magnesium concentrations, immunoglobulin titres and

  15. Histamine prevents polyamine accumulation in mouse C57.1 mast cell cultures.

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    Fajardo, I; Urdiales, J L; Paz, J C; Chavarría, T; Sánchez-Jiménez, F; Medina, M A

    2001-02-01

    The effects of histamine on polyamine uptake and metabolism was studied in a mouse mast cell line (C57.1), as a cell model in which both biogenic amines are important for maintaining cell function and viability. Results obtained after incubations with exogenous histamine indicated that histamine prevents polyamine accumulation by affecting polyamine uptake. A plasma membrane transport system for polyamines has been also studied in mast cells. It seems to be a Na(+)-dependent uptake with high affinity for both spermine and spermidine and lower affinity for putrescine and agmatine. Polyamine uptake was reduced in both cells treated with exogenous histamine and histamine-preloaded cells. However, ornithine decarboxylase activity and cell proliferation were not affected by histamine. Incubation with histamine enhanced the spermidine/spermine acetyl transferase induction caused by N(1)-ethyl-N(11)-[(cyclopropyl)methyl]-4,8-diazaundecane, suggesting that polyamine acetylation could be another mechanism by which histamine prevents polyamine accumulation in C57.1 mast cells.

  16. Germ Granules Prevent Accumulation of Somatic Transcripts in the Adult Caenorhabditis elegans Germline.

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    Knutson, Andrew Kekūpa'a; Egelhofer, Thea; Rechtsteiner, Andreas; Strome, Susan

    2017-05-01

    The germ cells of multicellular organisms protect their developmental potential through specialized mechanisms. A shared feature of germ cells from worms to humans is the presence of nonmembrane-bound, ribonucleoprotein organelles called germ granules. Depletion of germ granules in Caenorhabditis elegans (i.e., P granules) leads to sterility and, in some germlines, expression of the neuronal transgene unc-119::gfp and the muscle myosin MYO-3 Thus, P granules are hypothesized to maintain germ cell totipotency by preventing somatic development, although the mechanism by which P granules carry out this function is unknown. In this study, we performed transcriptome and single molecule RNA-FISH analyses of dissected P granule-depleted gonads at different developmental stages. Our results demonstrate that P granules are necessary for adult germ cells to downregulate spermatogenesis RNAs and to prevent the accumulation of numerous soma-specific RNAs. P granule-depleted gonads that express the unc-119::gfp transgene also express many other genes involved in neuronal development and concomitantly lose expression of germ cell fate markers. Finally, we show that removal of either of two critical P-granule components, PGL-1 or GLH-1, is sufficient to cause germ cells to express UNC-119::GFP and MYO-3 and to display RNA accumulation defects similar to those observed after depletion of P granules. Our data identify P granules as critical modulators of the germline transcriptome and guardians of germ cell fate. Copyright © 2017 by the Genetics Society of America.

  17. Srs2 and Mus81-Mms4 Prevent Accumulation of Toxic Inter-Homolog Recombination Intermediates.

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    Kenji Keyamura

    2016-07-01

    Full Text Available Homologous recombination is an evolutionally conserved mechanism that promotes genome stability through the faithful repair of double-strand breaks and single-strand gaps in DNA, and the recovery of stalled or collapsed replication forks. Saccharomyces cerevisiae ATP-dependent DNA helicase Srs2 (a member of the highly conserved UvrD family of helicases has multiple roles in regulating homologous recombination. A mutation (srs2K41A resulting in a helicase-dead mutant of Srs2 was found to be lethal in diploid, but not in haploid, cells. In diploid cells, Srs2K41A caused the accumulation of inter-homolog joint molecule intermediates, increased the levels of spontaneous Rad52 foci, and induced gross chromosomal rearrangements. Srs2K41A lethality and accumulation of joint molecules were suppressed by inactivating Rad51 or deleting the Rad51-interaction domain of Srs2, whereas phosphorylation and sumoylation of Srs2 and its interaction with sumoylated proliferating cell nuclear antigen (PCNA were not required for lethality. The structure-specific complex of crossover junction endonucleases Mus81 and Mms4 was also required for viability of diploid, but not haploid, SRS2 deletion mutants (srs2Δ, and diploid srs2Δ mus81Δ mutants accumulated joint molecule intermediates. Our data suggest that Srs2 and Mus81-Mms4 have critical roles in preventing the formation of (or in resolving toxic inter-homolog joint molecules, which could otherwise interfere with chromosome segregation and lead to genetic instability.

  18. BRCA2 Regulates Transcription Elongation by RNA Polymerase II to Prevent R-Loop Accumulation

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    Mahmud K.K. Shivji

    2018-01-01

    Full Text Available The controlled release of RNA polymerase II (RNAPII from promoter-proximal pausing (PPP sites is critical for transcription elongation in metazoans. We show that the human tumor suppressor BRCA2 interacts with RNAPII to regulate PPP release, thereby preventing unscheduled RNA-DNA hybrids (R-loops implicated in genomic instability and carcinogenesis. BRCA2 inactivation by depletion or cancer-causing mutations instigates RNAPII accumulation and R-loop accrual at PPP sites in actively transcribed genes, accompanied by γH2AX formation marking DNA breakage, which is reduced by ERCC4 endonuclease depletion. BRCA2 inactivation decreases RNAPII-associated factor 1 (PAF1 recruitment (which normally promotes RNAPII release and diminishes H2B Lys120 ubiquitination, impeding nascent RNA synthesis. PAF1 depletion phenocopies, while its overexpression ameliorates, R-loop accumulation after BRCA2 inactivation. Thus, an unrecognized role for BRCA2 in the transition from promoter-proximal pausing to productive elongation via augmented PAF1 recruitment to RNAPII is subverted by disease-causing mutations, provoking R-loop-mediated DNA breakage in BRCA2-deficient cells.

  19. Vitamin E prevents neutrophil accumulation and attenuates tissue damage in ischemic-reperfused human skeletal muscle.

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    Formigli, L; Ibba Manneschi, L; Tani, A; Gandini, E; Adembri, C; Pratesi, C; Novelli, G P; Zecchi Orlandini, S

    1997-07-01

    Neutrophil accumulation and the consequent production of oxygen-derived free radicals are involved in the pathogenesis of Ischemia-Reperfusion syndrome. In this study we investigated whether a treatment with Vitamin E, which has antioxidant properties, could attenuate the tissue damage by interfering with the influx of neutrophils within the ischemic and reperfused human skeletal muscle. To this purpose, patients undergoing aortic cross-clamping during the surgical repair of aortic abdominal aneurysm were studied as a model of ischemia-reperfusion of the lower limb muscles. Muscle biopsies from the right femoral quadriceps of patients not receiving and receiving Vitamin E pretreatment before surgery were taken: a) after the induction of anaesthesia, as control samples, and b) after a period of ischemia followed by 30 min of reperfusion. The tissue samples were either routinely processed for morphological study and immunohistochemical analysis to detect an altered expression of specific endothelial adhesion proteins, such as E-selectin and ICAM-1. The results obtained showed that Vitamin E administration was able to prevent the accumulation of neutrophils within the ischemic and reperfused muscle. This beneficial effect of Vitamin E was due to its ability to hinder the expression of E-selectin and ICAM-1, molecules known to increase the adhesiveness of endothelium to circulating neutrophils. After treatment with Vitamin E a marked attenuation of the reperfusion injury was also evident. In conclusion, Vitamin E treatment may be considered a valuable tool for protection against the ischemia-reperfusion damage of human skeletal muscle.

  20. Treatment of erythrocytes with the 2-cys peroxiredoxin inhibitor, Conoidin A, prevents the growth of Plasmodium falciparum and enhances parasite sensitivity to chloroquine.

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    Mariana Brizuela

    Full Text Available The human erythrocyte contains an abundance of the thiol-dependant peroxidase Peroxiredoxin-2 (Prx2, which protects the cell from the pro-oxidant environment it encounters during its 120 days of life in the blood stream. In malarial infections, the Plasmodium parasite invades red cells and imports Prx2 during intraerythrocytic development, presumably to supplement in its own degradation of peroxides generated during cell metabolism, especially hemoglobin (Hb digestion. Here we demonstrate that an irreversible Prx2 inhibitor, Conoidin A (2,3-bis(bromomethyl-1,4-dioxide-quinoxaline; BBMQ, has potent cytocidal activity against cultured P. falciparum. Parasite growth was also inhibited in red cells that were treated with BBMQ and then washed prior to parasite infection. These cells remained susceptible to merozoite invasion, but failed to support normal intraerythrocytic development. In addition the potency of chloroquine (CQ, an antimalarial drug that prevents the detoxification of Hb-derived heme, was significantly enhanced in the presence of BBMQ. CQ IC50 values decreased an order of magnitude when parasites were either co-incubated with BBMQ, or introduced into BBMQ-pretreated cells; these effects were equivalent for both drug-resistant and drug-sensitive parasite lines. Together these results indicate that treatment of red cells with BBMQ renders them incapable of supporting parasite growth and increases parasite sensitivity to CQ. We also propose that molecules such as BBMQ that target host cell proteins may constitute a novel host-directed therapeutic approach for treating malaria.

  1. A role of phosphatidylserine externalization in clearance of erythrocytes exposed to stress but not in eliminating aging populations of erythrocyte in mice.

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    Khandelwal, Sanjay; Saxena, Rajiv K

    2008-08-01

    Age dependent changes in phosphatidylserine (PS) externalization were studied in mouse erythrocytes of different age groups (range 1-55 days) by using a newly developed double in vivo biotinylation (DIB) technique. Around 3-4% of the erythrocytes freshly released in the circulation were PS(+) but this proportion fell rapidly to 1% or less and did not increase at later time points. Blocking erythrocyte clearance from the circulation by in vivo depletion of macrophages (by treatment with clodronate loaded liposomes) for up to 7 days did not result in accumulation of PS(+) erythrocytes in the circulation indicating that the low percentage of PS(+) cells within old erythrocytes (age >40 days) was not related to the clearance of PS(+) erythrocytes by macrophages. In vitro treatment with stress inducing agents like deoxyglucose or Ca(++)/calcium ionophore resulted in a marked induction of PS externalization in mouse erythrocytes and this effect was most prominent in the youngest erythrocyte population (age erythrocytes after intravenous infusion into recipient mice indicated that the young erythrocytes were cleared at fastest rate from the circulation as compared to erythrocytes of older age groups. Within young erythrocytes exposed to stress, PS(+) erythrocytes were preferentially cleared. Taken together our results suggest that PS externalization is unlikely to have a role in the removal of old erythrocytes from blood circulation but may have a role in the clearance of stressed and damaged young erythrocytes in blood circulation.

  2. Accumulation of long-chain glycosphingolipids during aging is prevented by caloric restriction.

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    María José Hernández-Corbacho

    Full Text Available BACKGROUND: Chronic kidney disease and end-stage renal disease are major causes of morbidity and mortality that are seen far more commonly in the aged population. Interestingly, kidney function declines during aging even in the absence of underlying renal disease. Declining renal function has been associated with age-related cellular damage and dysfunction with reports of increased levels of apoptosis, necrosis, and inflammation in the aged kidney. Bioactive sphingolipids have been shown to regulate these same cellular processes, and have also been suggested to play a role in aging and cellular senescence. METHODOLOGY/PRINCIPAL FINDINGS: We hypothesized that alterations in kidney sphingolipids play a role in the declining kidney function that occurs during aging. To begin to address this, the sphingolipid profile was measured in young (3 mo, middle aged (9 mo and old (17 mo C57BL/6 male mice. Interestingly, while modest changes in ceramides and sphingoid bases were evident in kidneys from older mice, the most dramatic elevations were seen in long-chain hexosylceramides (HexCer and lactosylceramides (LacCer, with C14- and C16-lactosylceramides elevated as much as 8 and 12-fold, respectively. Increases in long-chain LacCers during aging are not exclusive to the kidney, as they also occur in the liver and brain. Importantly, caloric restriction, previously shown to prevent the declining kidney function seen in aging, inhibits accumulation of long-chain HexCer/LacCers and prevents the age-associated elevation of enzymes involved in their synthesis. Additionally, long-chain LacCers are also significantly elevated in human fibroblasts isolated from elderly individuals. CONCLUSION/SIGNIFICANCE: This study demonstrates accumulation of the glycosphingolipids HexCer and LacCer in several different organs in rodents and humans during aging. In addition, data demonstrate that HexCer and LacCer metabolism is regulated by caloric restriction. Taken together

  3. Enzymatic assay for methotrexate in erythrocytes

    DEFF Research Database (Denmark)

    Schrøder, H; Heinsvig, E M

    1985-01-01

    Methotrexate (MTX) accumulates in erythrocytes in MTX-treated patients. We present a modified enzymatic assay measuring MTX concentrations between 10 and 60 nmol/l in erythrocytes, adapted for a centrifugal analyser (Cobas Bio). About 40 patient's samples could be analysed within 1 h. The detection...... limit was 3 nmol/l. Within run and between-run precision was 7.4% and 13.5% for control 10 nmol/l and 1.2% and 3.2% for control 50 nmol/l. Recovery was 85-115% of MTX added to haemolysed erythrocytes. We found the method useful for pharmacokinetic studies of MTX in erythrocytes in MTX-treated patients...

  4. Role of Nrf2 in preventing ethanol-induced oxidative stress and lipid accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Kai Connie [Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Liu, Jie [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Klaassen, Curtis D., E-mail: cklaasse@kumc.edu [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States)

    2012-08-01

    Oxidative stress and lipid accumulation play important roles in alcohol-induced liver injury. Previous reports showed that, in livers of nuclear factor erythroid 2-related factor 2 (Nrf2)-activated mice, genes involved in antioxidant defense are induced, whereas genes involved in lipid biosynthesis are suppressed. To investigate the role of Nrf2 in ethanol-induced hepatic alterations, Nrf2-null mice, wild-type mice, kelch-like ECH-associated protein 1-knockdown (Keap1-KD) mice with enhanced Nrf2, and Keap1-hepatocyte knockout (Keap1-HKO) mice with maximum Nrf2 activation, were treated with ethanol (5 g/kg, po). Blood and liver samples were collected 6 h thereafter. Ethanol increased alanine aminotransferase and lactate dehydrogenase activities as well as thiobarbituric acid reactive substances in serum of Nrf2-null and wild-type mice, but not in Nrf2-enhanced mice. After ethanol administration, mitochondrial glutathione concentrations decreased markedly in Nrf2-null mice but not in Nrf2-enhanced mice. H{sub 2}DCFDA staining of primary hepatocytes isolated from the four genotypes of mice indicates that oxidative stress was higher in Nrf2-null cells, and lower in Nrf2-enhanced cells than in wild-type cells. Ethanol increased serum triglycerides and hepatic free fatty acids in Nrf2-null mice, and these increases were blunted in Nrf2-enhanced mice. In addition, the basal mRNA and nuclear protein levels of sterol regulatory element-binding protein 1(Srebp-1) were decreased with graded Nrf2 activation. Ethanol further induced Srebp-1 mRNA in Nrf2-null mice but not in Nrf2-enhanced mice. In conclusion, Nrf2 activation prevented alcohol-induced oxidative stress and accumulation of free fatty acids in liver by increasing genes involved in antioxidant defense and decreasing genes involved in lipogenesis. -- Highlights: ► Ethanol depleted mitochondrial GSH in Nrf2-null mice but not in Keap1-KD mice. ► Ethanol increased ROS in hepatocytes isolated from Nrf2-null and wild

  5. Storage of Erythrocytes Induces Suicidal Erythrocyte Death

    National Research Council Canada - National Science Library

    Lang, Elisabeth; Pozdeev, Vitaly I; Xu, Haifeng C; Shinde, Prashant V; Behnke, Kristina; Hamdam, Junnat M; Lehnert, Erik; Scharf, Rüdiger E; Lang, Florian; Häussinger, Dieter; Lang, Karl S; Lang, Philipp A

    2016-01-01

    .... In this study, we explored whether storage of RBC influences the rate of eryptosis. Flow cytometry was employed to quantify phosphatidylserine exposing erythrocytes from annexin V binding and cytosolic Ca2...

  6. Prevention of age-induced N(ε)-(carboxymethyl)lysine accumulation in the microvasculature.

    Science.gov (United States)

    Fuijkschot, Wessel W; de Graaff, Hjalmar J; Berishvili, Ekatarina; Kakabadze, Zurab; Kupreishvili, Koba; Meinster, Elisa; Houtman, Maaike; van Broekhoven, Amber; Schalkwijk, Casper G; Vonk, Alexander B A; Krijnen, Paul A J; Smulders, Yvo M; Niessen, Hans W N

    2016-04-01

    N(ε)-(carboxymethyl)lysine (CML) is one of the major advanced glycation end products in both diabetics and nondiabetics. CML depositions in the microvasculature have recently been linked to the aetiology of acute myocardial infarction and cognitive impairment in Alzheimer's disease, possibly related to local enhancement of inflammation and oxidative processes. We hypothesized that CML deposition in the microvasculature of the heart and brain is age-induced and that it could be inhibited by a diet intervention with docosahexaenoic acid (DHA), an omega-3 fatty acid known for its anti-inflammatory and antioxidative actions. ApoE(-/-) mice (n = 50) were fed a Western diet and were sacrificed after 40, 70 and 90 weeks. Part of these mice (n = 20) were fed a Western diet enriched with DHA from 40 weeks on. CML in cardiac and cerebral microvessels was quantified using immunohistochemistry. Cardiac microvascular depositions of CML significantly increased with an immunohistochemical score of 11·85 [5·92-14·60] at 40 weeks, to 33·17 [17·60-47·15] at 70 weeks (P = 0·005). At the same time points, cerebral microvascular CML increased from 6·45; [4·78-7·30] to 12·99; [9·85-20·122] (P = 0·003). DHA decreased CML in the intramyocardial vasculature at both 70 and 90 weeks, significant at 70 weeks [33·17; (17·60-47·15) vs. 14·73; (4·44-28·16) P = 0·037]. No such effects were found in the brain. Accumulation of N(ε)-(carboxymethyl)lysine in the cerebral and cardiac microvasculature is age-induced and is prevented by DHA in the intramyocardial vessels of ApoE(-/-) mice. © 2016 Stichting European Society for Clinical Investigation Journal Foundation.

  7. Effects of Preventive Acupuncture and Moxibustion on Fat Accumulation, Blood Lipid, and Uterus E2 of Menopause Rats

    Directory of Open Access Journals (Sweden)

    Shi-Peng Zhu

    2014-01-01

    Full Text Available Objective. To observe the effect of preventive acupuncture and moxibustion on blood lipid of menopause rats. Methods. Seventy 10-month-old SD rats with estrous cycle disorders were divided into three control groups and four treatment groups (n=10/group and another ten 3.5-month-old female SD rats were chosen as young control group. Preventive acupuncture and moxibustion were applied at Guanyuan (CV 4. Body weight growth rate has been recorded. Plasma total cholesterol (TC, triglyceride (TG, low density lipoprotein (LDL, and high density lipoprotein (HDL levels and uterus E2 level were measured. Results. Compared to young control group, plasma TC and LDL increased and uterus E2 reduced significantly in 12-month-old control group. Compared to 12-month-old control group, plasma TC and LDL level and body weight growth rate decreased while HDL level increased remarkably in preventive acupuncture 12-month-old group. Compared to 14-month-old control group, plasma TC level and body weight growth rate decreased remarkably in preventive moxibustion 14-month-old group. Conclusions. Preventive acupuncture and moxibustion can significantly decrease the plasma TG and LDL, increase the plasma HDL, and prevent fat accumulation. Our finding suggests that preventive acupuncture and moxibustion have beneficial effects on blood lipid. Different treatment effects were found between preventive acupuncture and preventive moxibustion.

  8. Effects of Preventive Acupuncture and Moxibustion on Fat Accumulation, Blood Lipid, and Uterus E 2 of Menopause Rats

    Science.gov (United States)

    He, Yu-wei; Chen, Huan; Sun, Zhi-Fang; Ding, Na; Mo, Jie; Cao, Bing-Yan; Luo, Li; Zhang, Qing-Qing; Wang, Yang; Zhang, Lu-Fen; Ren, Xiao-Xuan; Guo, Meng-Wei; Zhao, Ya-Fang; Ma, Liang-Xiao; Li, Xiao-Hong

    2014-01-01

    Objective. To observe the effect of preventive acupuncture and moxibustion on blood lipid of menopause rats. Methods. Seventy 10-month-old SD rats with estrous cycle disorders were divided into three control groups and four treatment groups (n = 10/group) and another ten 3.5-month-old female SD rats were chosen as young control group. Preventive acupuncture and moxibustion were applied at Guanyuan (CV 4). Body weight growth rate has been recorded. Plasma total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), and high density lipoprotein (HDL) levels and uterus E 2 level were measured. Results. Compared to young control group, plasma TC and LDL increased and uterus E 2 reduced significantly in 12-month-old control group. Compared to 12-month-old control group, plasma TC and LDL level and body weight growth rate decreased while HDL level increased remarkably in preventive acupuncture 12-month-old group. Compared to 14-month-old control group, plasma TC level and body weight growth rate decreased remarkably in preventive moxibustion 14-month-old group. Conclusions. Preventive acupuncture and moxibustion can significantly decrease the plasma TG and LDL, increase the plasma HDL, and prevent fat accumulation. Our finding suggests that preventive acupuncture and moxibustion have beneficial effects on blood lipid. Different treatment effects were found between preventive acupuncture and preventive moxibustion. PMID:24639882

  9. Blockage of mitochondrial calcium uniporter prevents iron accumulation in a model of experimental subarachnoid hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Huiying [Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province (China); Hao, Shuangying; Sun, Xiaoyan [Jiangsu Key Laboratory for Molecular Medicine, Medical School of Nanjing University, 22 Hankou Road, Nanjing 210093, Jiangsu Province (China); Zhang, Dingding; Gao, Xin; Yu, Zhuang [Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province (China); Li, Kuanyu, E-mail: likuanyu@nju.edu.cn [Jiangsu Key Laboratory for Molecular Medicine, Medical School of Nanjing University, 22 Hankou Road, Nanjing 210093, Jiangsu Province (China); Hang, Chun-Hua, E-mail: hang_neurosurgery@163.com [Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province (China)

    2015-01-24

    Highlights: • Iron accumulation was involved in the acute phase following SAH. • Blockage of MCU could attenuate cellular iron accumulation following SAH. • Blockage of MCU could decrease ROS generation and improve cell energy supply following SAH. • Blockage of MCU could alleviate apoptosis and brain injury following SAH. - Abstract: Previous studies have shown that iron accumulation is involved in the pathogenesis of brain injury following subarachnoid hemorrhage (SAH) and chelation of iron reduced mortality and oxidative DNA damage. We previously reported that blockage of mitochondrial calcium uniporter (MCU) provided benefit in the early brain injury after experimental SAH. This study was undertaken to identify whether blockage of MCU could ameliorate iron accumulation-associated brain injury following SAH. Therefore, we used two reagents ruthenium red (RR) and spermine (Sper) to inhibit MCU. Sprague–Dawley (SD) rats were randomly divided into four groups including sham, SAH, SAH + RR, and SAH + Sper. Biochemical analysis and histological assays were performed. The results confirmed the iron accumulation in temporal lobe after SAH. Interestingly, blockage of MCU dramatically reduced the iron accumulation in this area. The mechanism was revealed that inhibition of MCU reversed the down-regulation of iron regulatory protein (IRP) 1/2 and increase of ferritin. Iron–sulfur cluster dependent-aconitase activity was partially conserved when MCU was blocked. In consistence with this and previous report, ROS levels were notably reduced and ATP supply was rescued; levels of cleaved caspase-3 dropped; and integrity of neurons in temporal lobe was protected. Taken together, our results indicated that blockage of MCU could alleviate iron accumulation and the associated injury following SAH. These findings suggest that the alteration of calcium and iron homeostasis be coupled and MCU be considered to be a therapeutic target for patients suffering from SAH.

  10. Dietary Protein Affects Gene Expression and Prevents Lipid Accumulation in the Liver in Mice

    NARCIS (Netherlands)

    Schwarz, J.; Tome, D.G.; Baars, A.; Hooiveld, G.J.E.J.; Müller, M.R.

    2012-01-01

    Background and Aims: High protein (HP) diets are suggested to positively modulate obesity and associated increased prevalence of non-alcoholic fatty liver (NAFLD) disease in humans and rodents. The aim of our study was to detect mechanisms by which a HP diet affects hepatic lipid accumulation.

  11. Erythrocyte membrane fractions contain free barbed filament ends despite sufficient concentrations of retained capper(s) to prevent barbed end growth.

    Science.gov (United States)

    DiNubile, M J

    1999-01-01

    Many cellular functions depend on rapid cytoskeletal rearrangements localized to specific cytoplasmic domains. Tight regulation of the submembranous microfilament network is accomplished in large part in erythrocytes and granulocytes by actin binding proteins that cap the fast-growing barbed filament ends. Study of this dynamic system is necessarily hampered by the confounding perturbations of cell lysis and dilution. In this paper, we characterize the functional properties of the membrane-associated spectrin-actin complex from human erythrocytes as it exists after hypotonic lysis. Purified spectrin-actin "seeds" extracted from erythrocyte membranes effectively nucleated actin elongation from their barbed ends. However, polymerization from spectrin-actin complexes associated with the membrane fraction prematurely slowed despite the presence of G-actin in great excess of the critical monomer concentration. The addition of cytochalasin B decreased (rather than augmented) the slowing of elongation attributable to the membrane fraction, indicating that capping of barbed filament ends (not monomer sequestration) was the major mechanism underlying this effect. The paradoxical implication of our findings is that, despite the presence of excess capper(s) in the membrane fraction, the membrane-associated spectrin-actin seeds were not capped until after dilution into physiological ionic strength buffer containing monomeric actin. Furthermore, by comparing the degrees of contamination of the extracted and membrane-associated spectrin-actin preparations, it appeared that recognized capping proteins (including gelsolin and capping protein beta2) were not the predominant cappers found in the membrane pellet after hypotonic lysis. We hypothesize that the barbed ends of membrane-associated spectrin-actin complexes, while not excluding actin monomers, may be selectively inaccessible to certain cappers (perhaps simply as the result of steric hindrance). Growth from such complexes in

  12. Clofazimine Induced Suicidal Death of Human Erythrocytes

    National Research Council Canada - National Science Library

    Officioso, Arbace; Alzoubi, Kousi; Manna, Caterina; Lang, Florian

    2015-01-01

    .... In erythrocytes phospholipase A2 stimulates eryptosis, the suicidal erythrocyte death characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface...

  13. Interaction with Penicillium expansum enhances Botrytis cinerea growth in grape juice medium and prevents patulin accumulation in vitro.

    Science.gov (United States)

    Morales, H; Paterson, R R M; Venâncio, A; Lima, N

    2013-05-01

    Interactions between fungi occur when they grow on the same host plant. This is the case of Botrytis cinerea and Penicillium expansum on grape. P. expansum is also responsible for production of the mycotoxin patulin. In this study, the influence of the interaction between both fungi on fungal growth parameters was studied as well as the effect on the accumulation of patulin by P. expansum. For that purpose, spores of B. cinerea and P. expansum were inoculated together (mixed inoculum), and the parameters growth rate, time for growth and patulin accumulation were assessed. The presence of P. expansum conidia shortened the time for growth of mixed inoculum colonies which, at the end of incubation, were B. cinerea-like. Although some P. expansum growth was observed in mixed inoculum colonies, very low levels of patulin were observed. In assays carried out in patulin-spiked medium, B. cinerea was capable to metabolize the mycotoxin. The capabilities of B. cinerea to shorten time for growth and prevent patulin accumulation are competing abilities that facilitate grape colonization. © 2013 The Society for Applied Microbiology.

  14. PRKAA1/AMPKα1 is required for autophagy-dependent mitochondrial clearance during erythrocyte maturation

    Science.gov (United States)

    Zhu, Huaiping; Foretz, Marc; Xie, Zhonglin; Zhang, Miao; Zhu, Zhiren; Xing, Junjie; Leclerc, Jocelyne; Gaudry, Murielle; Viollet, Benoit; Zou, Ming-Hui

    2014-01-01

    AMP-activated protein kinase α1 knockout (prkaa1−/−) mice manifest splenomegaly and anemia. The underlying molecular mechanisms, however, remain to be established. In this study, we tested the hypothesis that defective autophagy-dependent mitochondrial clearance in prkaa1−/− mice exacerbates oxidative stress, thereby enhancing erythrocyte destruction. The levels of ULK1 phosphorylation, autophagical flux, mitochondrial contents, and reactive oxygen species (ROS) were examined in human erythroleukemia cell line, K562 cells, as well as prkaa1−/− mouse embryonic fibroblasts and erythrocytes. Deletion of Prkaa1 resulted in the inhibition of ULK1 phosphorylation at Ser555, prevented the formation of ULK1 and BECN1- PtdIns3K complexes, and reduced autophagy capacity. The suppression of autophagy was associated with enhanced damaged mitochondrial accumulation and ROS production. Compared with wild-type (WT) mice, prkaa1−/− mice exhibited a shortened erythrocyte life span, hemolytic destruction of erythrocytes, splenomegaly, and anemia, all of which were alleviated by the administration of either rapamycin to activate autophagy or Mito-tempol, a mitochondria-targeted antioxidant, to scavenge mitochondrial ROS. Furthermore, transplantation of WT bone marrow into prkaa1−/− mice restored mitochondrial removal, reduced intracellular ROS levels, and normalized hematologic parameters and spleen size. Conversely, transplantation of prkaa1 −/− bone marrow into WT mice recapitulated the prkaa1−/− mouse phenotypes. We conclude that PRKAA1-dependent autophagy-mediated clearance of damaged mitochondria is required for erythrocyte maturation and homeostasis. PMID:24988326

  15. [Erythrocytic enzymopathy in Uzbekistan].

    Science.gov (United States)

    Bakhramov, S M; Ashrabhodzhaeva, K K

    2011-01-01

    Erythrocyte enzymes participate in the main interactions promoting utilization of glucose-glycolytic, pentosophosphate cycles and glutation system. In this report we study on erythrocyte G6PD deficiency which is the impairment related to the gender and expressed with development of acute drug-associated hemolytic anemia. Out of 13187 studied subjects 122 showed carrying of deficiency of erythrocyte G6PD activity, from them 98 (80.3%) subjects were male, and 24 (19.7%) female. As a whole, among the revealed in the population studies, and also verified in clinic of the persons with deficiency of erythrocyte G6PD there were marked different pathological phenotypes: hereditary nonspherecytary hemolytic anemia, acute drug-induced hemolytic anemia, asymptomatic gene carrying and, selected by us disease with few symptoms. As a whole, among the revealed in the population studies, and also verified in clinic of the persons with deficiency of erythrocyte G6PD there were marked different pathological phenotypes: hereditary nonspherecytary hemolytic anemia, acute drug-induced hemolytic anemia, asymptomatic gene carrying and, selected by us disease with few symptoms.

  16. Maternal Antiviral Immunoglobulin Accumulates in Neural Tissue of Neonates To Prevent HSV Neurological Disease

    Directory of Open Access Journals (Sweden)

    Yike Jiang

    2017-07-01

    Full Text Available While antibody responses to neurovirulent pathogens are critical for clearance, the extent to which antibodies access the nervous system to ameliorate infection is poorly understood. In this study on herpes simplex virus 1 (HSV-1, we demonstrate that HSV-specific antibodies are present during HSV-1 latency in the nervous systems of both mice and humans. We show that antibody-secreting cells entered the trigeminal ganglion (TG, a key site of HSV infection, and persisted long after the establishment of latent infection. We also demonstrate the ability of passively administered IgG to enter the TG independently of infection, showing that the naive TG is accessible to antibodies. The translational implication of this finding is that human fetal neural tissue could contain HSV-specific maternally derived antibodies. Exploring this possibility, we observed HSV-specific IgG in HSV DNA-negative human fetal TG, suggesting passive transfer of maternal immunity into the prenatal nervous system. To further investigate the role of maternal antibodies in the neonatal nervous system, we established a murine model to demonstrate that maternal IgG can access and persist in neonatal TG. This maternal antibody not only prevented disseminated infection but also completely protected the neonate from neurological disease and death following HSV challenge. Maternal antibodies therefore have a potent protective role in the neonatal nervous system against HSV infection. These findings strongly support the concept that prevention of prenatal and neonatal neurotropic infections can be achieved through maternal immunization.

  17. ESR (Erythrocyte Sedimentation Rate) Test

    Science.gov (United States)

    ... products and services. Advertising & Sponsorship: Policy | Opportunities Erythrocyte Sedimentation Rate (ESR) Share this page: Was this page helpful? Also known as: Sed Rate; Sedimentation Rate; Westergren Sedimentation Rate Formal name: Erythrocyte Sedimentation ...

  18. Kinetics of extracellular ATP in mastoparan 7-activated human erythrocytes

    Science.gov (United States)

    Denis, María Florencia Leal; Incicco, J. Jeremías; Espelt, María Victoria; Verstraeten, Sandra V.; Pignataro, Omar P.; Lazarowski, Eduardo R.; Schwarzbaum, Pablo J.

    2014-01-01

    SUMMARY Background The peptide mastoparan 7 (MST7) stimulated ATP release in human erythrocytes. We explored intra- and extracellular processes governing the time-dependent accumulation of extracellular ATP (i.e., ATPe kinetics). Methods Human erythrocytes were treated with MST7 in the presence or absence of two blockers of pannexin 1. ATPe concentration was monitored by luciferin-luciferase based real-time luminometry. Results Exposure of human erythrocytes to MST7 led to an acute increase in [ATPe], followed by a slower increase phase. ATPe kinetics reflected a strong activation of ATP efflux and a low rate of ATPe hydrolysis by ectoATPase activity. Enhancement of [ATPe] by MST7 required adhesion of erythrocytes to poly-D-lysin-coated coverslips, and correlated with a 31% increase of cAMP and 10% cell swelling. However, when MST7 was dissolved in a hyperosmotic medium to block cell swelling, ATPe accumulation was inhibited by 49%. Erythrocytes pre-exposure to 10 μM of either carbenoxolone or probenecid, two blockers of pannexin 1, exhibited a partial reduction of ATP efflux. Erythrocytes from pannexin 1 knockout mice exhibited similar ATPe kinetics as those of wild type mice erythrocytes exposed to pannexin 1 blockers. Conclusions MST7 induced release of ATP required either cell adhesion or strong activation of cAMP synthesis. Part of this release required cell swelling. Kinetic analysis and a data driven model suggested that ATP efflux is mediated by two ATP conduits displaying different kinetics, with one conduit being fully blocked by pannexin 1 blockers. General Significance Kinetic analysis of extracellular ATP accumulation from human erythrocytes and potential effects on microcirculation. PMID:23742824

  19. METOVITAN PREVENTS THE ACCUMULATION OF THIAMINE DIPHOSPHATE OXIDIZED FORM IN RAT TISSUES UNDER IRRADIATION

    Directory of Open Access Journals (Sweden)

    Parkhomenko Yu. M.

    2015-08-01

    Full Text Available The aim of the research was to test the ability of the drug "Metovitan" to prevent the redox balance disturbance in the tissues and thiamine diphosphate irreversible oxidation upon exposure of ionizing radiation on the body. The rats were subjected to a single exposure of the X-ray therapeutic instrument RUM-17 to create a dose of 0.5, 1.0 and 5.0 Gray. Preparation "Metovitan" was administered at a dose of 25 mg per 1 kg body weight for 22–24 h before irradiation. Contents of thiamine diphosphate, reduced SH-groups and reactive oxygen species in blood and brain were determined using previously described methods. It has been shown that the active form of the thiamine diphosphate content in the blood was decreased depending on the doses (from 0.5 to 5.0 Gray. At the same time the content of thiamine diphosphate oxidized form was increased. Furthermore the critical changes occurred in metabolic processes redox state parameters, namely, the level of free SH-groups was reduced and the level of reactive oxygen species was increased. Similar changes were observed in the brain tissue. The Metovitan single administration to the animals the day before irradiation, at 25 mg per 1 kg of body weight dose, promotes the protection of the intracellular thiamine diphosphate and redox status in animal tissues (blood, brain tissue from the negative influence of irradiation (at 0.5; 1.0 Gray doses. These results give reason to recommend the drug for treating of the staff that is involved in the elimination of radioactive contamination. To provide the protection from the higher doses, other scheme of the treatment should be probably recommended.

  20. Azelnidipine prevents cardiac dysfunction in streptozotocin-diabetic rats by reducing intracellular calcium accumulation, oxidative stress and apoptosis

    Directory of Open Access Journals (Sweden)

    Kain Vasundhara

    2011-11-01

    Full Text Available Abstract Background Numerous evidences suggest that diabetic heart is characterized by compromised ventricular contraction and prolonged relaxation attributable to multiple causative factors including calcium accumulation, oxidative stress and apoptosis. Therapeutic interventions to prevent calcium accumulation and oxidative stress could be therefore helpful in improving the cardiac function under diabetic condition. Methods This study was designed to examine the effect of long-acting calcium channel blocker (CCB, Azelnidipine (AZL on contractile dysfunction, intracellular calcium (Ca2+ cycling proteins, stress-activated signaling molecules and apoptosis on cardiomyocytes in diabetes. Adult male Wistar rats were made diabetic by a single intraperitoneal (IP injection of streptozotocin (STZ. Contractile functions were traced from live diabetic rats to isolated individual cardiomyocytes including peak shortening (PS, time-to-PS (TPS, time-to-relengthening (TR90, maximal velocity of shortening/relengthening (± dL/dt and intracellular Ca2+ fluorescence. Results Diabetic heart showed significantly depressed PS, ± dL/dt, prolonged TPS, TR90 and intracellular Ca2+ clearing and showed an elevated resting intracellular Ca2+. AZL itself exhibited little effect on myocyte mechanics but it significantly alleviated STZ-induced myocyte contractile dysfunction. Diabetes increased the levels of superoxide, enhanced expression of the cardiac damage markers like troponin I, p67phox NADPH oxidase subunit, restored the levels of the mitochondrial superoxide dismutase (Mn-SOD, calcium regulatory proteins RyR2 and SERCA2a, and suppressed the levels of the anti-apoptotic Bcl-2 protein. All of these STZ-induced alterations were reconciled by AZL treatment. Conclusion Collectively, the data suggest beneficial effect of AZL in diabetic cardiomyopathy via altering intracellular Ca2+ handling proteins and preventing apoptosis by its antioxidant property.

  1. Oxidative Hemolysis of Erythrocytes

    Science.gov (United States)

    Wlodek, Lidia; Kusior, Dorota

    2006-01-01

    This exercise for students will allow them to simultaneously observe lipid peroxidation and consequent hemolysis of rat erythrocytes and the effect of sodium azide, a catalase inhibitor, on these processes. It will also demonstrate a protective action of antioxidants, the therapeutically used N-acetylcysteine and albumins present in plasma.

  2. Metal Accumulation, Blood δ-Aminolevulinic Acid Dehydratase Activity and Micronucleated Erythrocytes of Feral pigeons (Columba Livia Living Near Former Lead-Zinc Smelter “ Trepça” – Kosovo

    Directory of Open Access Journals (Sweden)

    Elezaj I. R.

    2013-04-01

    Full Text Available The concentration of lead in blood and tibia (Pb, zinc (Zn and cupper (Cu in tibia, blood δ- aminolevulinic acid dehydratase (ALA-D; EC: 4.2.1.24 activity, hematocrit value (Hct and micronuclei frequency (MN of peripheral erythrocytes have been determinated in three different populations of feral pigeons (Columba livia; forma urbana and forma domestica, collected in Mitrovica town (situated close to smelter “Trepça”, down closed in 2000 year and in rural area (Koshare willage . The blood lead level in feral pigeons from Mitrovica (forma urbana was 3 times higher (149.6; 50.5 μg% in comparison with that in feral pigeons from Mitrovica (forma domestica and 27.7 times higher (5.4 μg% in comparison with pigeons from rural area. The Pb concentration of tibia of feral pigeons (froma urbana and forma domestica, from Mitrovica town was significantly higher (P<0.001 in comparison with control. The concentration of Zn in tibia of feral pigeons from Mitrovica town (forma urbana, was significantly higher (P<0.006 in comparison with control. The blood ALA-D activity of feral pigeons from Mitrovica town (forma urbana and froma domestica, was significantly inhibited in comparison with control. The blood ALA-D activity of feral pigeons –forma urbana from Mitrovica town was significantly inhibited (P<0.001 in comparison with the blood ALA-D activity of feral pigeons-forma domestica from Mitrovica town. The erythrocyte MN frequency of feral pigeons from Mitrovica was significantly higher (P <0.001 in comparison with controls. The smelter “Trepça” ten year after closed down pose a threat to the local environment, biota and people’s health.

  3. Myo/Nog cells: targets for preventing the accumulation of skeletal muscle-like cells in the human lens.

    Directory of Open Access Journals (Sweden)

    Jacquelyn Gerhart

    Full Text Available Posterior capsule opacification (PCO is a vision impairing condition that arises in some patients following cataract surgery. The fibrotic form of PCO is caused by myofibroblasts that may emerge in the lens years after surgery. In the chick embryo lens, myofibroblasts are derived from Myo/Nog cells that are identified by their expression of the skeletal muscle specific transcription factor MyoD, the bone morphogenetic protein inhibitor Noggin, and the epitope recognized by the G8 monoclonal antibody. The goal of this study was to test the hypothesis that depletion of Myo/Nog cells will prevent the accumulation of myofibroblasts in human lens tissue. Myo/Nog cells were present in anterior, equatorial and bow regions of the human lens, cornea and ciliary processes. In anterior lens tissue removed by capsulorhexis, Myo/Nog cells had synthesized myofibroblast and skeletal muscle proteins, including vimentin, MyoD and sarcomeric myosin. Alpha smooth muscle actin (α-SMA was detected in a subpopulation of Myo/Nog cells. Areas of the capsule denuded of epithelial cells were surrounded by Myo/Nog cells. Some of these cell free areas contained a wrinkle in the capsule. Depletion of Myo/Nog cells eliminated cells expressing skeletal muscle proteins in 5-day cultures but did not affect cells immunoreactive for beaded filament proteins that accumulate in differentiating lens epithelial cells. Transforming growth factor-betas 1 and 2 that mediate an epithelial-mesenchymal transition, did not induce the expression of skeletal muscle proteins in lens cells following Myo/Nog cell depletion. This study demonstrates that Myo/Nog cells in anterior lens tissue removed from cataract patients have undergone a partial differentiation to skeletal muscle. Myo/Nog cells appear to be the source of skeletal muscle-like cells in explants of human lens tissue. Targeting Myo/Nog cells with the G8 antibody during cataract surgery may reduce the incidence of PCO.

  4. Two Outer Membrane Proteins Contribute to Caulobacter crescentus Cellular Fitness by Preventing Intracellular S-Layer Protein Accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Overton, K. Wesley; Park, Dan M.; Yung, Mimi C.; Dohnalkova, Alice C.; Smit, John; Jiao, Yongqin; Parales, R. E.

    2016-09-23

    ABSTRACT

    Surface layers, or S-layers, are two-dimensional protein arrays that form the outermost layer of many bacteria and archaea. They serve several functions, including physical protection of the cell from environmental threats. The high abundance of S-layer proteins necessitates a highly efficient export mechanism to transport the S-layer protein from the cytoplasm to the cell exterior.Caulobacter crescentusis unique in that it has two homologous, seemingly redundant outer membrane proteins, RsaFaand RsaFb, which together with other components form a type I protein translocation pathway for S-layer export. These proteins have homology toEscherichia coliTolC, the outer membrane channel of multidrug efflux pumps. Here we provide evidence that, unlike TolC, RsaFaand RsaFbare not involved in either the maintenance of membrane stability or the active export of antimicrobial compounds. Rather, RsaFaand RsaFbare required to prevent intracellular accumulation and aggregation of the S-layer protein RsaA; deletion of RsaFaand RsaFbled to a general growth defect and lowered cellular fitness. Using Western blotting, transmission electron microscopy, and transcriptome sequencing (RNA-seq), we show that loss of both RsaFaand RsaFbled to accumulation of insoluble RsaA in the cytoplasm, which in turn caused upregulation of a number of genes involved in protein misfolding and degradation pathways. These findings provide new insight into the requirement for RsaFaand RsaFbin cellular fitness and tolerance to antimicrobial agents and further our understanding of the S-layer export mechanism on both the transcriptional and translational levels in

  5. Immune Evasion Strategies of Pre-Erythrocytic Malaria Parasites

    Directory of Open Access Journals (Sweden)

    Hong Zheng

    2014-01-01

    Full Text Available Malaria is a mosquito-borne infectious disease of humans. It begins with a bite from an infected female Anopheles mosquito and leads to the development of the pre-erythrocytic and blood stages. Blood-stage infection is the exclusive cause of clinical symptoms of malaria. In contrast, the pre-erythrocytic stage is clinically asymptomatic and could be an excellent target for preventive therapies. Although the robust host immune responses limit the development of the liver stage, malaria parasites have also evolved strategies to suppress host defenses at the pre-erythrocytic stage. This paper reviews the immune evasion strategies of malaria parasites at the pre-erythrocytic stage, which could provide us with potential targets to design prophylactic strategies against malaria.

  6. Stabilization of Erythrocyte Membranes by Polyamines

    Science.gov (United States)

    Ballas, Samir K.; Mohandas, Narla; Marton, Laurence J.; Shohet, Stephen B.

    1983-04-01

    Using a laser diffraction technique, we have studied the effects of putrescine, spermidine, and spermine, the three physiologic polyamines, on the deformability and mechanical stability of human erythrocyte membranes. Ghosts resealed with polyamines were subjected to high fluid shear stress in an ektacytometer. All polyamines increased the membrane shear modulus (decreased deformability) in a concentration- and time-dependent manner. The order of effectiveness was spermine > spermidine > putrescine. At 10 μ M, spermine appreciably decreased membrane deformability. For the measurement of membrane mechanical stability, resealed ghosts were subjected to constant high shear stress in the ektacytometer and deformability was continuously recorded as the deformable ghosts fragmented into rigid spherical vesicles. Polyamines, especially spermine, caused a noticeable increase in the t1/2 for fragmentation. These effects could not be ascribed to proteolysis or Ca2+-induced transglutamination. That the effects of polyamines were specific and not simply due to their positive charge was demonstrated by the finding that Ca2+ and Mg2+ destabilized the erythrocyte membrane as evidenced by decreasing the t1/2 for fragmentation. Extracellular polyamines were not effective except under conditions that caused significant accumulation inside the cell. The data indicate that intracellular physiologic polyamines, especially spermine, decrease erythrocyte membrane deformability and stabilize the membrane skeleton, making it more resistant to fragmentation.

  7. Cyclin A2 regulates erythrocyte morphology and numbers.

    Science.gov (United States)

    Jayapal, Senthil Raja; Ang, Heather Yin-Kuan; Wang, Chelsia Qiuxia; Bisteau, Xavier; Caldez, Matias J; Xuan, Gan Xiao; Yu, Weimiao; Tergaonkar, Vinay; Osato, Motomi; Lim, Bing; Kaldis, Philipp

    2016-11-16

    Cyclin A2 is an essential gene for development and in haematopoietic stem cells and therefore its functions in definitive erythropoiesis have not been investigated. We have ablated cyclin A2 in committed erythroid progenitors in vivo using erythropoietin receptor promoter-driven Cre, which revealed its critical role in regulating erythrocyte morphology and numbers. Erythroid-specific cyclin A2 knockout mice are viable but displayed increased mean erythrocyte volume and reduced erythrocyte counts, as well as increased frequency of erythrocytes containing Howell-Jolly bodies. Erythroblasts lacking cyclin A2 displayed defective enucleation, resulting in reduced production of enucleated erythrocytes and increased frequencies of erythrocytes containing nuclear remnants. Deletion of the Cdk inhibitor p27 Kip1 but not Cdk2, ameliorated the erythroid defects resulting from deficiency of cyclin A2, confirming the critical role of cyclin A2/Cdk activity in erythroid development. Loss of cyclin A2 in bone marrow cells in semisolid culture prevented the formation of BFU-E but not CFU-E colonies, uncovering its essential role in BFU-E function. Our data unveils the critical functions of cyclin A2 in regulating mammalian erythropoiesis.

  8. Determination of somatic mutations in human erythrocytes by cytometry

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, R.H.; Langlois, R.G.; Bigbee, W.L.

    1985-06-21

    Flow cytometric assays of human erythrocytes labeled with monoclonal antibodies specific for glycophorin A were used to enumerate variant cells that appear in peripheral blood as a result of somatic gene-loss mutations in erythrocyte precursor cells. The assay was performed on erythrocytes from 10 oncology patients who had received at least one treatment from radiation or mutagenic chemotherapy at least 3 weeks before being assayed. The patients were suffering from many different malignancies (e.g., breast, renal, bone, colon and lung), and were treated with several different mutagenic therapeutics (e.g., cisplatinum, adriamycin, daunomycin, or cyclophosphamide). The frequency of these variant cells is an indication of the amount of mutagenic damage accumulated in the individual's erythropoietic cell population. Comparing these results to HPRT clonogenic assays, we find similar baseline frequencies of somatic mutation as well as similar correlation with mutagenic exposures. 9 refs., 3 figs., 1 tab.

  9. MODIFICATION OF ERYTHROCYTE MEMBRANE PROTEINS WITH POLYETHYLENE GLYCOL 1500

    Directory of Open Access Journals (Sweden)

    N. G. Zemlianskykh

    2016-10-01

    Full Text Available The aim of the work was to study the effect of polyethylene glycol PEG-1500 on the Ca2+-ATPase activity and changes in CD44 surface marker expression in human erythrocyte membranes. Determination of the Ca2+-ATPase activity was carried out in sealed erythrocyte ghosts by the level of accumulation of inorganic phosphorus. Changes in the expression of CD44 and amount of CD44+-erythrocytes were evaluated by flow cytometry. The inhibition of Ca2+-ATPase activity and a reduction in the level of CD44 expression and also the decrease in the amount CD44+-cells were found, reflecting a fairly complex restructuring in the membrane-cytoskeleton complex of erythrocytes under the influence of PEG-1500. Effect of PEG-1500 on the surface CD44 marker could be mediated by modification of proteins of membrane-cytoskeleton complex, as indicated by accelerated loss of CD44 in erythrocyte membranes after application of protein cross-linking reagent diamide. Reduced activity of Ca2+-ATPase activity may contribute to the increase in intracellular Ca2+ level and thus leads to a modification of interactions of integral proteins with cytoskeletal components that eventually could result in membrane vesiculation and decreasing in expression of the CD44 marker, which is dynamically linked to the cytoskeleton.

  10. Triggering of suicidal erythrocyte death by uremic toxin indoxyl sulfate

    Science.gov (United States)

    2013-01-01

    Background Anemia in end stage renal disease is attributed to impaired erythrocyte formation due to erythropoietin and iron deficiency. On the other hand, end stage renal disease enhances eryptosis, the suicidal erythrocyte death characterized by cell shrinkage and phosphatidylserine-exposure at the erythrocyte surface. Eryptosis may be triggered by increase of cytosolic Ca2+-activity ([Ca2+]i) and by ceramide, which sensitizes erythrocytes to [Ca2+]i. Mechanisms triggering eryptosis in endstage renal disease remained enigmatic. The present study explored the effect of indoxyl sulfate, an uremic toxin accumulated in blood of patients with chronic kidney disease. Methods Cell volume was estimated from forward scatter, phosphatidylserine-exposure from annexin V binding, ceramide abundance by specific antibodies, hemolysis from hemoglobin release, and [Ca2+]i from Fluo3-fluorescence. Results A 48 hours exposure to indoxyl sulfate significantly increased [Ca2+]i (≥ 300 μM), significantly decreased forward scatter (≥ 300 μM) and significantly increased annexin-V-binding (≥ 50 μM). Indoxyl sulfate (150 μM) induced annexin-V-binding was virtually abolished in the nominal absence of extracellular Ca2+. Indoxyl sulfate (150 μM) further enhanced ceramide abundance. Conclusion Indoxyl sulfate stimulates suicidal erythrocyte death or eryptosis, an effect in large part due to stimulation of extracellular Ca2+entry with subsequent stimulation of cell shrinkage and cell membrane scrambling. PMID:24188099

  11. Suppression of Reactive Oxygen Species Accumulation in Chloroplasts Prevents Leaf Damage but Not Growth Arrest in Salt-Stressed Tobacco Plants.

    Science.gov (United States)

    Lodeyro, Anabella F; Giró, Mariana; Poli, Hugo O; Bettucci, Gabriel; Cortadi, Adriana; Ferri, Alejandro M; Carrillo, Néstor

    2016-01-01

    Crop yield reduction due to salinity is a growing agronomical concern in many regions. Increased production of reactive oxygen species (ROS) in plant cells accompanies many abiotic stresses including salinity, acting as toxic and signaling molecules during plant stress responses. While ROS are generated in various cellular compartments, chloroplasts represent a main source in the light, and plastid ROS synthesis and/or elimination have been manipulated to improve stress tolerance. Transgenic tobacco plants expressing a plastid-targeted cyanobacterial flavodoxin, a flavoprotein that prevents ROS accumulation specifically in chloroplasts, displayed increased tolerance to many environmental stresses, including drought, excess irradiation, extreme temperatures and iron starvation. Surprisingly, flavodoxin expression failed to protect transgenic plants against NaCl toxicity. However, when high salt was directly applied to leaf discs, flavodoxin did increase tolerance, as reflected by preservation of chlorophylls, carotenoids and photosynthetic activities. Flavodoxin decreased salt-dependent ROS accumulation in leaf tissue from discs and whole plants, but this decline did not improve tolerance at the whole plant level. NaCl accumulation in roots, as well as increased osmotic pressure and salt-induced root damage, were not prevented by flavodoxin expression. The results indicate that ROS formed in chloroplasts have a marginal effect on plant responses during salt stress, and that sensitive targets are present in roots which are not protected by flavodoxin.

  12. The impact of accumulated experience on children's appraisals of risk and risk-taking decisions: implications for youth injury prevention.

    Science.gov (United States)

    Lasenby-Lessard, Jennifer; Morrongiello, Barbara A; Barrie, Deb

    2013-04-01

    This study assessed whether repeated experience with a physical activity leads to increased risk taking and compared what factors (risk appraisals, emotion ratings, child attributes) predict risk taking before and after practice doing the activity. Children 7 to 12 years of age participated in an ecologically valid risk-taking task in which they chose the highest height at which to set a balance beam before and after they practiced walking across it. Prior to accumulating experience, predictors of risk taking included appraisals of risk, child attributes, and extent of past experience with the activity. After accumulating experience, risk taking increased and was predicted by behavioral attributes (low inhibitory control, high sensation seeking) and appraisal of perceived vulnerability. When aiming to reduce risk taking, the best approach will be one that targets different determinants depending on children's extent of experience with the recreational activity. 2013 APA, all rights reserved

  13. Effects of Preventive Acupuncture and Moxibustion on Fat Accumulation, Blood Lipid, and Uterus E2 of Menopause Rats

    OpenAIRE

    Shi-Peng Zhu; Yu-wei He; Huan Chen; Zhi-Fang Sun; Na Ding; Jie Mo; Bing-Yan Cao; Li Luo; Qing-Qing Zhang; Yang Wang; Lu-Fen Zhang; Xiao-Xuan Ren; Meng-Wei Guo; Ya-Fang Zhao; Liang-Xiao Ma

    2014-01-01

    Objective. To observe the effect of preventive acupuncture and moxibustion on blood lipid of menopause rats. Methods. Seventy 10-month-old SD rats with estrous cycle disorders were divided into three control groups and four treatment groups (n = 10/group) and another ten 3.5-month-old female SD rats were chosen as young control group. Preventive acupuncture and moxibustion were applied at Guanyuan (CV 4). Body weight growth rate has been recorded. Plasma total cholesterol (TC), triglyceride (...

  14. Dopamine prevents lipid peroxidation-induced accumulation of toxic α-synuclein oligomers by preserving autophagy-lysosomal function

    Science.gov (United States)

    Jiang, Peizhou; Gan, Ming; Yen, Shu-Hui C.

    2013-01-01

    The formation of Lewy bodies containing α-synuclein (α-syn), prominent loss of dopaminergic neurons and dopamine (DA) deficiency in substantia nigra and striatum are histopathological and biochemical hallmarks of Parkinson’s disease (PD). Multiple lines of evidence have indicated that a critical pathogenic factor causing PD is enhanced production of reactive oxygen species (ROS), which reacts readily with polyunsaturated fatty acids to cause lipid peroxidation (LPO). LPO products have been shown to facilitate assembly of toxic α-syn oligomers in in vitro studies. Since DA is prone to autoxidation and cause ROS, it has been suggested that interactions among DA, LPO, and α-syn play an important role in neuronal loss in PD. However, the exact mechanism(s) remains unclear. We addressed this issue using a neuronal cell model which inducibly expresses human wild-type α-syn by the tetracycline off (Tet-Off) mechanism and stably expresses high levels of DA transporter. Under retinoic acid elicited neuronal differentiation, cells with or without overexpressing α-syn and with or without exposure to LPO inducer-arachidonic acid (AA), plus 0–500 μM of DA were assessed for the levels of LPO, α-syn accumulation, cell viability, and autophagy. AA exposure elicited similar LPO levels in cells with and without α-syn overexpression, but significantly enhanced the accumulation of α-syn oligomers and monomers only in cultures with Tet-Off induction and decreased cell survival in a LPO-dependent manner. Surprisingly, DA at low concentrations (100 μM), DA exposure enhanced the toxic effects of AA. To our knowledge, this is the first report showing biphasic effects of DA on neuronal survival and α-syn accumulation. PMID:23754979

  15. Cheese consumption prevents fat accumulation in the liver and improves serum lipid parameters in rats fed a high-fat diet

    OpenAIRE

    Higurashi, Satoshi; Ogawa, Akihiro; Nara, Takayuki Y.; Kato, Ken; Kadooka, Yukio

    2016-01-01

    International audience; AbstractCheese consumption has been reported to reduce the risk of metabolic syndrome; however, the mechanisms by which cheese prevents these disorders are not fully understood. The purpose of this study was to examine the effects of cheese consumption on lipid accumulation in the liver as well as to evaluate various serum lipid parameters. Two groups (n = 7) of male Fischer-344 rats were fed the following high-fat diets for 9 weeks: AIN76-modified 20% fat diet contain...

  16. FACT prevents the accumulation of free histones evicted from transcribed chromatin and a subsequent cell cycle delay in G1.

    Directory of Open Access Journals (Sweden)

    Macarena Morillo-Huesca

    2010-05-01

    Full Text Available The FACT complex participates in chromatin assembly and disassembly during transcription elongation. The yeast mutants affected in the SPT16 gene, which encodes one of the FACT subunits, alter the expression of G1 cyclins and exhibit defects in the G1/S transition. Here we show that the dysfunction of chromatin reassembly factors, like FACT or Spt6, down-regulates the expression of the gene encoding the cyclin that modulates the G1 length (CLN3 in START by specifically triggering the repression of its promoter. The G1 delay undergone by spt16 mutants is not mediated by the DNA-damage checkpoint, although the mutation of RAD53, which is otherwise involved in histone degradation, enhances the cell-cycle defects of spt16-197. We reveal how FACT dysfunction triggers an accumulation of free histones evicted from transcribed chromatin. This accumulation is enhanced in a rad53 background and leads to a delay in G1. Consistently, we show that the overexpression of histones in wild-type cells down-regulates CLN3 in START and causes a delay in G1. Our work shows that chromatin reassembly factors are essential players in controlling the free histones potentially released from transcribed chromatin and describes a new cell cycle phenomenon that allows cells to respond to excess histones before starting DNA replication.

  17. Current status of erythrocyte substitutes.

    Science.gov (United States)

    Biro, G. P.

    1983-01-01

    During the last two decades the search for alternatives to whole blood transfusions has led to promising developments in the field of erythrocyte substitutes. Hemoglobin solutions free of fragments of erythrocyte stroma and fluorocarbon emulsions are not blood-type-specific and appear likely to satisfy some proportion of our blood requirements. Both must be modified before becoming clinically useful. The oxygen affinity of the hemoglobin solution must be reduced and its intravascular persistence improved. Fluorocarbons cannot yet contribute significantly to the oxygen supply unless the patient breathes hyperbaric oxygen. Recent advances are leading to solutions for these problems. PMID:6344974

  18. Hexanoic Acid Treatment Prevents Systemic MNSV Movement in Cucumis melo Plants by Priming Callose Deposition Correlating SA and OPDA Accumulation

    OpenAIRE

    Emma Fernández-Crespo; Navarro, Jose A.; Marta Serra-Soriano; Iván Finiti; Pilar García-Agustín; Vicente Pallás; Carmen González-Bosch

    2017-01-01

    Unlike fungal and bacterial diseases, no direct method is available to control viral diseases. The use of resistance-inducing compounds can be an alternative strategy for plant viruses. Here we studied the basal response of melon to Melon necrotic spot virus (MNSV) and demonstrated the efficacy of hexanoic acid (Hx) priming, which prevents the virus from systemically spreading. We analysed callose deposition and the hormonal profile and gene expression at the whole plant level. This allowed u...

  19. Triggers, Inhibitors, Mechanisms, and Significance of Eryptosis: The Suicidal Erythrocyte Death

    Directory of Open Access Journals (Sweden)

    Elisabeth Lang

    2015-01-01

    Full Text Available Suicidal erythrocyte death or eryptosis is characterized by erythrocyte shrinkage, cell membrane blebbing, and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include Ca2+ entry, ceramide formation, stimulation of caspases, calpain activation, energy depletion, oxidative stress, and dysregulation of several kinases. Eryptosis is triggered by a wide variety of xenobiotics. It is inhibited by several xenobiotics and endogenous molecules including NO and erythropoietin. The susceptibility of erythrocytes to eryptosis increases with erythrocyte age. Phosphatidylserine exposing erythrocytes adhere to the vascular wall by binding to endothelial CXC-Motiv-Chemokin-16/Scavenger-receptor for phosphatidylserine and oxidized low density lipoprotein (CXCL16. Phosphatidylserine exposing erythrocytes are further engulfed by phagocytosing cells and are thus rapidly cleared from circulating blood. Eryptosis eliminates infected or defective erythrocytes thus counteracting parasitemia in malaria and preventing detrimental hemolysis of defective cells. Excessive eryptosis, however, may lead to anemia and may interfere with microcirculation. Enhanced eryptosis contributes to the pathophysiology of several clinical disorders including metabolic syndrome and diabetes, malignancy, cardiac and renal insufficiency, hemolytic uremic syndrome, sepsis, mycoplasma infection, malaria, iron deficiency, sickle cell anemia, thalassemia, glucose 6-phosphate dehydrogenase deficiency, and Wilson’s disease. Facilitating or inhibiting eryptosis may be a therapeutic option in those disorders.

  20. Triggers, Inhibitors, Mechanisms, and Significance of Eryptosis: The Suicidal Erythrocyte Death

    Science.gov (United States)

    Lang, Elisabeth

    2015-01-01

    Suicidal erythrocyte death or eryptosis is characterized by erythrocyte shrinkage, cell membrane blebbing, and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include Ca2+ entry, ceramide formation, stimulation of caspases, calpain activation, energy depletion, oxidative stress, and dysregulation of several kinases. Eryptosis is triggered by a wide variety of xenobiotics. It is inhibited by several xenobiotics and endogenous molecules including NO and erythropoietin. The susceptibility of erythrocytes to eryptosis increases with erythrocyte age. Phosphatidylserine exposing erythrocytes adhere to the vascular wall by binding to endothelial CXC-Motiv-Chemokin-16/Scavenger-receptor for phosphatidylserine and oxidized low density lipoprotein (CXCL16). Phosphatidylserine exposing erythrocytes are further engulfed by phagocytosing cells and are thus rapidly cleared from circulating blood. Eryptosis eliminates infected or defective erythrocytes thus counteracting parasitemia in malaria and preventing detrimental hemolysis of defective cells. Excessive eryptosis, however, may lead to anemia and may interfere with microcirculation. Enhanced eryptosis contributes to the pathophysiology of several clinical disorders including metabolic syndrome and diabetes, malignancy, cardiac and renal insufficiency, hemolytic uremic syndrome, sepsis, mycoplasma infection, malaria, iron deficiency, sickle cell anemia, thalassemia, glucose 6-phosphate dehydrogenase deficiency, and Wilson's disease. Facilitating or inhibiting eryptosis may be a therapeutic option in those disorders. PMID:25821808

  1. Agglutination of Mouse Erythrocytes by Eperythrozoon coccoides

    Science.gov (United States)

    Iralu, Vichazelhu; Ganong, Kevin D.

    1983-01-01

    Erythrocytes from blood of mice infected with Eperythrozoon coccoides for 3 or 4 days agglutinated spontaneously. Washed E. coccoides particles agglutinated washed erythrocytes of uninfected mice. E. coccoides-mediated agglutination of normal mouse erythrocytes would be an excellent system for studies of bacterial adhesion. Images PMID:6832825

  2. Agglutination of Mouse Erythrocytes by Eperythrozoon coccoides

    OpenAIRE

    Iralu, Vichazelhu; Ganong, Kevin D.

    1983-01-01

    Erythrocytes from blood of mice infected with Eperythrozoon coccoides for 3 or 4 days agglutinated spontaneously. Washed E. coccoides particles agglutinated washed erythrocytes of uninfected mice. E. coccoides-mediated agglutination of normal mouse erythrocytes would be an excellent system for studies of bacterial adhesion.

  3. Preventive effect of Ibrolipim on suppressing lipid accumulation and increasing lipoprotein lipase in the kidneys of diet-induced diabetic minipigs

    Directory of Open Access Journals (Sweden)

    Li Hong

    2011-07-01

    Full Text Available Abstract Background The role of renal lipoprotein lipase (LPL per se in kidney diseases is still controversial and obscure. The purpose of this study was to observe the preventive effects of Ibrolipim, a LPL activator, on lipid accumulation and LPL expression in the kidneys of minipigs fed a high-sucrose and high-fat diet (HSFD. Methods Male Chinese Bama minipigs were fed a control diet or HSFD with or without 0.1 g/kg/day Ibrolipim for 5 months. Body weight, plasma glucose, insulin, lipids, LPL activity, and urinary microalbumin were measured. Renal tissue was obtained for detecting LPL activity and contents of triglyceride and cholesterol, observing the renal lipid accumulation by Oil Red O staining, and examining the mRNA and protein expression of LPL by real time PCR, Western Blot and immunohistochemistry. Results Feeding HSFD to minipigs caused weight gain, hyperglycemia, hyperinsulinemia, hyperlipidemia and microalbuminuria. HSFD increased plasma LPL activity while it decreased the mRNA and protein expression and activity of LPL in the kidney. The increases in renal triglyceride and cholesterol contents were associated with the decrease in renal LPL activity of HSFD-fed minipigs. In contrast, supplementing Ibrolipim into HSFD lowered body weight, plasma glucose, insulin, triglyceride and urinary albumin concentrations while it increased plasma total cholesterol and HDL-C. Ibrolipim suppressed the renal accumulation of triglyceride and cholesterol, and stimulated the diet-induced down-regulation of LPL expression and activity in the kidney. Conclusions Ibrolipim exerts renoprotective and hypolipidemic effects via the increase in renal LPL activity and expression, and thus the increased expression and activity of renal LPL play a vital role in suppressing renal lipid accumulation and ameliorating proteinuria in diet-induced diabetic minipigs.

  4. Erythrocyte membrane skeleton inhibits nanoparticle endocytosis

    Science.gov (United States)

    Gao, Xinli; Yue, Tongtao; Tian, Falin; Liu, Zhiping; Zhang, Xianren

    2017-06-01

    Red blood cells (RBCs), also called erythrocytes, have been experimentally proposed in recent decades as the biological drug delivery systems through entrapping certain drugs by endocytosis. However, the internalization pathway of endocytosis seems to conflict with the robust mechanical properties of RBCs that is induced by the spectrin-actin network of erythrocyte membrane skeleton. In this work, we employed a minimum realistic model and the dissipative particle dynamics method to investigate the influence of the spectrin-actin membrane skeleton on the internalization of nanoparticles (NPs). Our simulations show that the existence of skeleton meshwork indeed induces an inhibiting effect that effectively prevents NPs from internalization. The inhibiting effect is found to depend on the membrane-NP attraction, skeleton tension and relative size of the NP to the membrane skeleton mesh. However, our simulations also demonstrate that there are two possibilities for successful internalization of NPs in the presence of the membrane skeleton. The first case is for NPs that has a much smaller size than the dimension of skeleton meshes, and the other is that the skeleton tension is rather weak so that the formed vesicle can still move inward for NP internalization.

  5. Mycoplasma gallisepticum Invades Chicken Erythrocytes during Infection▿

    Science.gov (United States)

    Vogl, Gunther; Plaickner, Astrid; Szathmary, Susan; Stipkovits, László; Rosengarten, Renate; Szostak, Michael P.

    2008-01-01

    Recently, it was demonstrated using in vitro assays that the avian pathogen Mycoplasma gallisepticum is able to invade nonphagocytic cells. It was also shown that this mycoplasma can survive and multiply intracellularly for at least 48 h and that this cell invasion capacity contributes to the systemic spread of M. gallisepticum from the respiratory tract to the inner organs. Using the gentamicin invasion assay and a differential immunofluorescence technique combined with confocal laser scanning microscopy, we were able to demonstrate in in vitro experiments that M. gallisepticum is also capable of invading sheep and chicken erythrocytes. The frequencies of invasion of three well-defined M. gallisepticum strains were examined over a period of 24 h, and a significant increase in invasiveness occurred after 8 h of infection. In addition, blood samples derived from chickens experimentally infected via the aerosol route with the virulent strain M. gallisepticum Rlow were analyzed. Surprisingly, M. gallisepticum Rlow was detected in the bloodstream of infected chickens by nested PCR, as well as by differential immunofluorescence and interference contrast microscopy that showed that mycoplasmas were not only on the surface but also inside chicken erythrocytes. This finding provides novel insight into the pathomechanism of M. gallisepticum and may have implications for the development of preventive strategies. PMID:17954728

  6. Mycoplasma gallisepticum invades chicken erythrocytes during infection.

    Science.gov (United States)

    Vogl, Gunther; Plaickner, Astrid; Szathmary, Susan; Stipkovits, László; Rosengarten, Renate; Szostak, Michael P

    2008-01-01

    Recently, it was demonstrated using in vitro assays that the avian pathogen Mycoplasma gallisepticum is able to invade nonphagocytic cells. It was also shown that this mycoplasma can survive and multiply intracellularly for at least 48 h and that this cell invasion capacity contributes to the systemic spread of M. gallisepticum from the respiratory tract to the inner organs. Using the gentamicin invasion assay and a differential immunofluorescence technique combined with confocal laser scanning microscopy, we were able to demonstrate in in vitro experiments that M. gallisepticum is also capable of invading sheep and chicken erythrocytes. The frequencies of invasion of three well-defined M. gallisepticum strains were examined over a period of 24 h, and a significant increase in invasiveness occurred after 8 h of infection. In addition, blood samples derived from chickens experimentally infected via the aerosol route with the virulent strain M. gallisepticum R(low) were analyzed. Surprisingly, M. gallisepticum R(low) was detected in the bloodstream of infected chickens by nested PCR, as well as by differential immunofluorescence and interference contrast microscopy that showed that mycoplasmas were not only on the surface but also inside chicken erythrocytes. This finding provides novel insight into the pathomechanism of M. gallisepticum and may have implications for the development of preventive strategies.

  7. [Anti-erythrocyte and anti-HLA immunization in hemoglobinopathies].

    Science.gov (United States)

    Ben Salah, N; El Borgi, W; Ben Lakhal, F; Ben Mansour, M; Gouider, E; Gorgi, Y; Bardi, R; Zoueri, B; Hafsia, R

    2014-12-01

    Evaluate the anti-erythrocyte and anti-HLA immunization rates in hemoglobinopathies. Cross-sectional study (October 2009-March 2010) on 83 patients followed for hemoglobinopathies. The irregular antibodies research is realized by two techniques: indirect Coombs and enzymatic technique on gel cards. The search for anti-HLA class I antibodies is done by complement dependent lymphocytotoxicity. The mean age was 30 years (14-64 years), the sex ratio M/F is 0.84. Our series included 42 cases of sickle cell disease (29 homozygous sickle cell anemia and 13 sickle-thalassemia) and 41 cases of thalassemia syndromes (26 major and 15 intermediate). The anti-erythrocyte alloimmunization rate is 10.84% without difference between thalassemia syndromes and sickle cell disease. The autoimmunization rate (22.89%) is higher in thalassemia syndromes (41.46%) than in the sickle cell disease (7.14%) (P<0.001). The anti-HLA immunization rate is 31.6% without difference between thalassemia syndromes and sickle cell disease. The young age, transfusion at a young age and the total number of transfusions are the factors that increase the risk of anti-erythrocyte autoimmunization. No clinicobiological parameter does influence the anti-erythrocyte and anti-HLA alloimmunization. There is no significant association between anti-erythrocyte and anti-HLA immunization. The erythrocyte and anti-HLA anti-immunization rates are high in our series. Preventive strategy is needed to ensure optimal blood safety. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  8. Hepatic confinement of newly produced erythrocytes caused by low-temperature exposure in Xenopus laevis.

    Science.gov (United States)

    Maekawa, Shun; Iemura, Hitomi; Kuramochi, Yuko; Nogawa-Kosaka, Nami; Nishikawa, Hironori; Okui, Takehito; Aizawa, Youichi; Kato, Takashi

    2012-09-01

    Diminished erythrocyte count and erythropoiesis have been reported during hypothermia in some ectothermic animals. In this study, the African clawed frog, Xenopus laevis, was used to investigate the cause of hypothermia-induced anemia. We developed a new model of hypothermia at 5°C and monitored blood cell count and erythropoiesis on several days. Erythrocyte count declined by 30% on the first day following cold exposure (5°C) and mRNA expression of hemeoxygenase-1 was enhanced 10-fold; accumulation of iron as a result of heme degradation was observed in the liver. One day after low-temperature exposure, erythropoietin mRNA expression was elevated in the liver and lung compared with that at normal temperature (22°C) by qRT-PCR analysis. Examination of liver sections (i.e. the erythropoietic organ) showed an increase in o-dianisidine-positive erythrocytes in the hepatic sinusoid 5 days after the onset of low-temperature exposure compared with normal liver. Peripheral erythrocyte count remained low, indicating that newly produced erythrocytes did not migrate from the liver to the circulation during hypothermia. In conclusion, this study reveals hypothermic anemia as being associated with hepatic erythrocyte destruction; prolonged anemia during low-temperature exposure is concomitant with newly produced erythrocytes being confined to the liver and may lead to new insights into vertebrate hematopoiesis.

  9. [A physical model of gravitational erythrocyte sedimentation].

    Science.gov (United States)

    Losev, E S

    1992-01-01

    A model of erythrocyte sedimentation under gravity is proposed. The model is based on two-phase description of the blood and it involves a kinetic equation of erythrocyte aggregation. A method of characteristics is employed for analysing the physical pattern of sedimentation for different hematocrit. An approximate decision for trajectory of the interface between pure plasma and low-located region of the erythrocyte suspension is obtained. By utilizing this decision the simple coefficient of the erythrocyte aggregation ability calculated in terms of hematocrit and erythrocyte sedimentation rate is possible.

  10. 6-gingerol prevents adipogenesis and the accumulation of cytoplasmic lipid droplets in 3T3-L1 cells.

    Science.gov (United States)

    Tzeng, Thing-Fong; Liu, I-Min

    2013-04-15

    6-Gingerol ((S)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-decanone) is one of the pungent constituents of Zingiber zerumbet (L) Smith (Zingiberaceae family). In this study, we investigated the effects of 6-gingerol on the inhibition of adipogenesis in 3T3-L1 cells. After treatment with 6-gingerol in differentiation medium for 4 or 8 days, the 3T3-L1 cells were lysed for experimental analysis. Cells were stained with Oil-Red-O to detect oil droplets in adipocytes. The 3T3-L1 cells were lysed and measured for triglyceride contents. The protein expression of adipogenesis-related transcription factor was evaluated by Western blot analysis. 6-Gingerol suppressed oil droplet accumulation and reduced the droplet size in a concentration (5-15 μg/ml)- and time-dependent manner. Treatment of 3T3-L1 cells with 6-gingerol reduced the protein levels of peroxisome proliferator-activated receptor (PPAR)γ and CCAAT/enhancer-binding protein (C/EBP)α. Additionally, the protein levels of fatty acid synthase (FAS) and adipocyte-specific fatty acid binding protein (aP2) decreased upon treatment with 6-gingerol. Meanwhile, 6-gingerol diminished the insulin-stimulated serine phosphorylation of Akt (Ser473) and GSK3β (Ser9). These results suggest that 6-gingerol effectively suppresses adipogenesis and that it exerts its role mainly through the significant down-regulation of PPARγ and C/EBPα and subsequently inhibits FAS and aP2 expression. 6-Gingerol also inhibited differentiation in 3T3-L1 cells by attenuating the Akt/GSK3β pathway. Our findings provide important insights into the mechanisms underlying the anti-adipogenic activity of 6-gingerol. Copyright © 2013 Elsevier GmbH. All rights reserved.

  11. Liver X Receptor Agonist TO901317 Prevents Diacylglycerols Accumulation in the Heart of Streptozotocin-Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Dorota Harasiuk

    2016-06-01

    Full Text Available Background/Aims: Liver X receptors (LXRα and LXRβ are ligand-activated transcription factors that regulate expression of genes involved in lipid and cholesterol metabolism. LXR expression has been identified in the heart, and enhanced LXR activity in the streptozotocin (STZ diabetic myocardium was reported recently. The aim of this study was to investigate effect of in vivo LXR activation on myocardial lipid metabolism under conditions of STZ-induced diabetes. Methods: Wistar rats were randomly divided into three experimental groups: non-diabetic control, treated with STZ, and treated with STZ and LXR agonist - TO901317. Diabetes was induced by a single intraperitonal injection of STZ at a dose of 55 mg/kg. LXR agonist was administrated once daily in the morning by an oral gavage at a dose of 10 mg/kg/d during the last week of the experiment. After anesthesia samples of blood and the left ventricle were taken. Results: TO901317 administration increased expression of both LXR isoforms and its target genes: sterol response element binding protein 1c (SREBP-1c and acetyl-coenzyme A carboxylase 1 (ACC1 in the heart of streptozotocin-diabetic rats. Treatment with LXR agonist had no effect on plasma lipids and glucose in the diabetic rats. Concomitantly, content of the examined lipid classes in the diabetic heart (nonesterified fatty acids, triacylglycerols, phospholipids, cholesterol esters, ceramide was unchanged after treatment with TO901317. On the contrary, myocardial level of cholesterol and diacylglycerols (DAG was decreased after LXR activation in diabetic rats, the change in DAG level was associated with downregulated expression of adipose triglyceride lipase (ATGL. Conclusion: Activation of LXRs by TO901317 protects cardiomyocytes against DAG accumulation and thus may reverse disturbances in lipid metabolism observed in streptozotocin-diabetic heart.

  12. Liver X Receptor Agonist TO901317 Prevents Diacylglycerols Accumulation in the Heart of Streptozotocin-Diabetic Rats.

    Science.gov (United States)

    Harasiuk, Dorota; Baranowski, Marcin; Zabielski, Piotr; Chabowski, Adrian; Górski, Jan

    2016-01-01

    Liver X receptors (LXRα and LXRβ) are ligand-activated transcription factors that regulate expression of genes involved in lipid and cholesterol metabolism. LXR expression has been identified in the heart, and enhanced LXR activity in the streptozotocin (STZ) diabetic myocardium was reported recently. The aim of this study was to investigate effect of in vivo LXR activation on myocardial lipid metabolism under conditions of STZ-induced diabetes. Wistar rats were randomly divided into three experimental groups: non-diabetic control, treated with STZ, and treated with STZ and LXR agonist - TO901317. Diabetes was induced by a single intraperitonal injection of STZ at a dose of 55 mg/kg. LXR agonist was administrated once daily in the morning by an oral gavage at a dose of 10 mg/kg/d during the last week of the experiment. After anesthesia samples of blood and the left ventricle were taken. TO901317 administration increased expression of both LXR isoforms and its target genes: sterol response element binding protein 1c (SREBP-1c) and acetyl-coenzyme A carboxylase 1 (ACC1) in the heart of streptozotocin-diabetic rats. Treatment with LXR agonist had no effect on plasma lipids and glucose in the diabetic rats. Concomitantly, content of the examined lipid classes in the diabetic heart (nonesterified fatty acids, triacylglycerols, phospholipids, cholesterol esters, ceramide) was unchanged after treatment with TO901317. On the contrary, myocardial level of cholesterol and diacylglycerols (DAG) was decreased after LXR activation in diabetic rats, the change in DAG level was associated with downregulated expression of adipose triglyceride lipase (ATGL). Activation of LXRs by TO901317 protects cardiomyocytes against DAG accumulation and thus may reverse disturbances in lipid metabolism observed in streptozotocin-diabetic heart. © 2016 The Author(s) Published by S. Karger AG, Basel.

  13. Emodin Prevents Intrahepatic Fat Accumulation, Inflammation and Redox Status Imbalance During Diet-Induced Hepatosteatosis in Rats

    Directory of Open Access Journals (Sweden)

    Valerio Nobili

    2012-02-01

    Full Text Available High-fat and/or high-carbohydrate diets may predispose to several metabolic disturbances including liver fatty infiltration (hepatosteatosis or be associated with necro-inflammation and fibrosis (steatohepatitis. Several studies have emphasized the hepatoprotective effect of some natural agents. In this study, we investigated the potential therapeutic effects of the treatment with emodin, an anthraquinone derivative with anti-oxidant and anti-cancer abilities, in rats developing diet-induced hepatosteatosis and steatohepatitis. Sprague-Dawley rats were fed a standard diet (SD for 15 weeks, or a high-fat/high-fructose diet (HFD/HF. After 5 weeks, emodin was added to the drinking water of some of the SD and HFD/HF rats. The experiment ended after an additional 10 weeks. Emodin-treated HFD/HF rats were protected from hepatosteatosis and metabolic derangements usually observed in HFD/HF animals. Furthermore, emodin exerted anti-inflammatory activity by inhibiting the HFD/HF-induced increase of tumor necrosis factor (TNF-α. Emodin also affected the hepatocytes glutathione homeostasis and levels of the HFD/HF-induced increase of glutathionylated/phosphorylated phosphatase and tensin homolog (PTEN. In conclusion, we demonstrated that a natural agent such as emodin can prevent hepatosteatosis, preserving liver from pro-inflammatory and pro-oxidant damage caused by HFD/HF diet. These findings are promising, proposing emodin as a possible hindrance to progression of hepatosteatosis into steatohepatitis.

  14. Salicornia herbacea prevents weight gain and hepatic lipid accumulation in obese ICR mice fed a high-fat diet.

    Science.gov (United States)

    Pichiah, P B Tirupathi; Cha, Youn-Soo

    2015-12-01

    Foods that are rich in fat and or sodium chloride promote obesity and associated diseases, whereas intake of dietary fiber averts obesity development. Salicornia herbacea (SH) is a rich source of dietary fiber and high in sodium chloride; therefore, we investigated whether replacing common salt with SH in a high-fat diet could prevent obesity development. Mice were divided into five groups: group ND was fed a normal diet, group HD was fed a high-fat diet, group HD-NaCl was fed a high fat diet with sodium chloride 10 g kg(-1) , group HD-CL was fed a high-fat diet with cellulose 30 g kg(-1) and group HD-SH was fed a high-fat diet with SH powder 50 g kg(-1) . The amount of sodium chloride and cellulose added in the respective diet was equivalent to their amount in SH. Data from our study showed that, SH supplementation significantly decreased body weight gain, liver weight, hepatic triglyceride, serum leptin and insulin, along with the mRNA level of key lipid anabolic genes such as SREBP-1c, PPARγ and FAS compared to the HD group. The results of this study demonstrated that SH is a potential natural anti-obesity agent that can be used in place of sodium chloride. © 2014 Society of Chemical Industry.

  15. Hexanoic Acid Treatment Prevents Systemic MNSV Movement in Cucumis melo Plants by Priming Callose Deposition Correlating SA and OPDA Accumulation

    Directory of Open Access Journals (Sweden)

    Emma Fernández-Crespo

    2017-10-01

    Full Text Available Unlike fungal and bacterial diseases, no direct method is available to control viral diseases. The use of resistance-inducing compounds can be an alternative strategy for plant viruses. Here we studied the basal response of melon to Melon necrotic spot virus (MNSV and demonstrated the efficacy of hexanoic acid (Hx priming, which prevents the virus from systemically spreading. We analysed callose deposition and the hormonal profile and gene expression at the whole plant level. This allowed us to determine hormonal homeostasis in the melon roots, cotyledons, hypocotyls, stems and leaves involved in basal and hexanoic acid-induced resistance (Hx-IR to MNSV. Our data indicate important roles of salicylic acid (SA, 12-oxo-phytodienoic acid (OPDA, jasmonic-isoleucine, and ferulic acid in both responses to MNSV. The hormonal and metabolites balance, depending on the time and location associated with basal and Hx-IR, demonstrated the reprogramming of plant metabolism in MNSV-inoculated plants. The treatment with both SA and OPDA prior to virus infection significantly reduced MNSV systemic movement by inducing callose deposition. This demonstrates their relevance in Hx-IR against MNSV and a high correlation with callose deposition. Our data also provide valuable evidence to unravel priming mechanisms by natural compounds.

  16. Bile acid binding resin prevents fat accumulation through intestinal microbiota in high-fat diet-induced obesity in mice.

    Science.gov (United States)

    Kusumoto, Yukie; Irie, Junichiro; Iwabu, Kaho; Tagawa, Hirotsune; Itoh, Arata; Kato, Mari; Kobayashi, Nana; Tanaka, Kumiko; Kikuchi, Rieko; Fujita, Masataka; Nakajima, Yuya; Morimoto, Kohkichi; Sugizaki, Taichi; Yamada, Satoru; Kawai, Toshihide; Watanabe, Mitsuhiro; Oike, Yuichi; Itoh, Hiroshi

    2017-06-01

    Bile acid binding resin (BAR) absorbs intestinal bile acids, and improves obesity and metabolic disorders, but the precise mechanism remains to be clarified. Recent findings reveal that obesity is associated with skewed intestinal microbiota. Thus, we investigated the effect of BAR on intestinal microbiota and the role of microbiota in the prevention of obesity in high-fat diet-induced obesity in mice. Male Balb/c mice were fed a low-fat diet (LFD), high-fat diet (HFD), or HFD with BAR (HFD+BAR), and then metabolic parameters, caecal microbiota, and metabolites were investigated. The same interventions were conducted in germ-free and antibiotic-treated mice. The frequency of Clostridium leptum subgroup was higher in both HFD-fed and HFD+BAR-fed mice than in LFD-fed mice. The frequency of Bacteroides-Prevotella group was lower in HFD-fed mice than in LFD-fed mice, but the frequency was higher in HFD+BAR-fed mice than in HFD-fed mice. Caecal propionate was lower in HFD-fed mice than in LFD-fed mice, and higher in HFD+BAR-fed mice than in HFD-fed mice. HFD+BAR-fed mice showed lower adiposity than HFD-fed mice, and the reduction was not observed in germ-free or antibiotic-treated mice. Colonized germ-free mice showed a reduction in adiposity by BAR administration. Energy expenditure was lower in HFD-fed mice and higher in HFD+BAR-fed mice, but the increments induced by administration of BAR were not observed in antibiotic-treated mice. Modulation of intestinal microbiota by BAR could be a novel therapeutic approach for obesity. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Viscoelastic behavior of erythrocyte membrane.

    Science.gov (United States)

    Tözeren, A; Skalak, R; Sung, K L; Chien, S

    1982-07-01

    A nonlinear viscoelastic relation is developed to describe the viscoelastic properties of erythrocyte membrane. This constitutive equation is used in the analysis of the time-dependent aspiration of an erythrocyte membrane into a micropipette. Equations governing this motion are reduced to a nonlinear integral equation of the Volterra type. A numerical procedure based on a finite difference scheme is used to solve the integral equation and to match the experimental data. The data, aspiration length vs. time, is used to determine the relaxation function at each time step. The inverse problem of obtaining the time dependence of the aspiration length from a given relaxation function is also solved. Analytical results obtained are applied to the experimental data of Chien et al. 1978. Biophys. J. 24:463-487. A relaxation function similar to that of a four-parameter solid with a shear-thinning viscous term is proposed.

  18. Spectroscopic analysis of irradiated erythrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Selim, Nabila S. [Biophysics Lab, Radiation Physics Department, National Center for Radiation Research and Technology (NCRRT), AEA, P.O. Box 29, Madinat Nasr, Cairo (Egypt); Desouky, Omar S., E-mail: omardesouky@yahoo.com [Biophysics Lab, Radiation Physics Department, National Center for Radiation Research and Technology (NCRRT), AEA, P.O. Box 29, Madinat Nasr, Cairo (Egypt); Ismail, Nagla M.; Dakrory, Amira Z. [Physics Department, Faculty of Girls for Arts, Sciences and Education, Ain Shams University, Cairo (Egypt)

    2011-12-15

    The aim of the present work is to study the effect of gamma radiation on the lipid part of the erythrocyte membrane, and to test the efficiency of lipoic acid as a radioprotector. This effect was evaluated using electron paramagnetic resonance (EPR), and Fourier transform infrared (FT-IR) spectroscopy. The results showed an increase in the number of spin density by 14%, 22% and 65% after exposure to 25, 50 and 100 Gy respectively; whereas there was a decline in the obtained density after incubation with lipoic acid by a factor of approximately 32%. The FT-IR spectra of the irradiated erythrocytes samples showed a marked decrease in the intensity of all characteristic peaks, which increased as the irradiation dose increased. The second-derivative of these spectra, allow the conformationally sensitive membrane acyl chain methylene stretching modes to be separated from the protein (mostly hemoglobin) vibrations that dominate the spectra of intact cells. The 2850 cm{sup -1} band showed changes in the band shape and position after exposure to 50 and 100 Gy. Therefore it can be concluded that the band at 2850 cm{sup -1} only is useful in monitoring the radiation effect of the lipids cell membrane intact cells. - Highlights: > Effect of {gamma} radiation on erythrocyte membrane was studied using EPR and FT-IR. > Efficiency of {alpha}-lipoic acid as radioprotector was tested. > Lipoic acid diminished the free radicals number after gamma irradiation by 32%. > FT-IR spectra of the irradiated erythrocyte showed a decrease in their intensity. > Lipoic acid enhances the membrane to resist the action of gamma radiation.

  19. Effects of nickel chloride on the erythrocytes and erythrocyte immune adherence function in broilers.

    Science.gov (United States)

    Li, Jian; Wu, Bangyuan; Cui, Hengmin; Peng, Xi; Fang, Jing; Zuo, Zhicai; Deng, Junliang; Wang, Xun; Tang, Kun; Yin, Shuang

    2014-11-01

    This study was conducted to investigate the immune adherence function of erythrocytes and erythrocyte induced by dietary nickel chloride (NiCl2) in broilers fed on a control diet and three experimental diets supplemented with 300, 600, and 900 mg/kg NiCl2 for 42 days. Blood samples were collected from five broilers in each group at 14, 28, and 42 days of age. Changes of erythrocyte parameters showed that total erythrocyte count (TEC), hemoglobin (Hb) contents, and packed cell volume (PCV) were significantly lower (p erythrocyte osmotic fragility (EOF) was higher (p erythrocyte immune adherence function indicated that erythrocyte C3b receptor rosette rate (E-C3bRR) was significantly decreased (p erythrocyte immune complex rosette rate (E-ICRR) was markedly increased (p erythrocytic integrity, erythrocytic ability to transport oxygen, and erythrocyte immune adherence function in broilers. Impairment of the erythrocytes and erythrocyte immune adherence function was one of main effect mechanisms of NiCl2 on the blood function.

  20. Exploitation of a newly-identified entry pathway into the malaria parasite-infected erythrocyte to inhibit parasite egress.

    Science.gov (United States)

    Glushakova, Svetlana; Busse, Brad L; Garten, Matthias; Beck, Josh R; Fairhurst, Rick M; Goldberg, Daniel E; Zimmerberg, Joshua

    2017-09-25

    While many parasites develop within host cells to avoid antibody responses and to utilize host cytoplasmic resources, elaborate egress processes have evolved to minimize the time between escaping and invading the next cell. In human erythrocytes, malaria parasites perforate their enclosing erythrocyte membrane shortly before egress. Here, we show that these pores clearly function as an entry pathway into infected erythrocytes for compounds that inhibit parasite egress. The natural glycosaminoglycan heparin surprisingly inhibited malaria parasite egress, trapping merozoites within infected erythrocytes. Labeled heparin neither bound to nor translocated through the intact erythrocyte membrane during parasite development, but fluxed into erythrocytes at the last minute of the parasite lifecycle. This short encounter was sufficient to significantly inhibit parasite egress and dispersion. Heparin blocks egress by interacting with both the surface of intra-erythrocytic merozoites and the inner aspect of erythrocyte membranes, preventing the rupture of infected erythrocytes but not parasitophorous vacuoles, and independently interfering with merozoite disaggregation. Since this action of heparin recapitulates that of neutralizing antibodies, membrane perforation presents a brief opportunity for a new strategy to inhibit parasite egress and replication.

  1. [AGGREGATION OF METABOLICALLY DEPLETED HUMAN ERYTHROCYTES].

    Science.gov (United States)

    Sheremet'ev, Yu A; Popovicheva, A N; Rogozin, M M; Levin, G Ya

    2016-01-01

    An aggregation of erythrocytes in autologous plasma after blood storage for 14 days at 4 °C was studied using photometry and light microscopy. The decrease of ATP content, the formation of echinocytes and spheroechinocytes, the decrease of rouleaux form of erythrocyte aggregation were observed during the storage. On the other hand the aggregates of echinocytes were formed in the stored blood. The addition of plasma from the fresh blood didn't restore the normal discocytic shape and aggregation of erythrocytes in the stored blood. The possible mechanisms of erythrocytes and echinocytes aggregation are discussed.

  2. Patulin-induced suicidal erythrocyte death

    National Research Council Canada - National Science Library

    Lupescu, Adrian; Jilani, Kashif; Zbidah, Mohanad; Lang, Florian

    2013-01-01

    .... Similar to apoptosis of nucleated cells, erythrocytes may enter suicidal death or eryptosis, which is characterized by cell shrinkage and by cell membrane scrambling leading to phosphatidylserine...

  3. Erythrocyte-derived microparticles supporting activated protein C-mediated regulation of blood coagulation.

    Science.gov (United States)

    Koshiar, Ruzica Livaja; Somajo, Sofia; Norström, Eva; Dahlbäck, Björn

    2014-01-01

    Elevated levels of erythrocyte-derived microparticles are present in the circulation in medical conditions affecting the red blood cells. Erythrocyte-derived microparticles expose phosphatidylserine thus providing a suitable surface for procoagulant reactions leading to thrombin formation via the tenase and prothrombinase complexes. Patients with elevated levels of circulating erythrocyte-derived microparticles have increased thrombin generation in vivo. The aim of the present study was to investigate whether erythrocyte-derived microparticles are able to support the anticoagulant reactions of the protein C system. Erythrocyte-derived microparticles were isolated using ultracentrifugation after incubation of freshly prepared erythrocytes with the ionophore A23187 or from outdated erythrocyte concentrates, the different microparticles preparations yielding similar results. According to flow cytometry analysis, the microparticles exposed phoshatidylserine and bound lactadherin, annexin V, and protein S, which is a cofactor to activated protein C. The microparticles were able to assemble the tenase and prothrombinase complexes and to stimulate the formation of thrombin in plasma-based thrombin generation assay both in presence and absence of added tissue factor. The addition of activated protein C in the thrombin generation assay inhibited thrombin generation in a dose-dependent fashion. The anticoagulant effect of activated protein C in the thrombin generation assay was inhibited by a monoclonal antibody that prevents binding of protein S to microparticles and also attenuated by anti-TFPI antibodies. In the presence of erythrocyte-derived microparticles, activated protein C inhibited tenase and prothrombinase by degrading the cofactors FVIIIa and FVa, respectively. Protein S stimulated the Arg306-cleavage in FVa, whereas efficient inhibition of FVIIIa depended on the synergistic cofactor activity of protein S and FV. In summary, the erythrocyte-derived microparticle

  4. Erythrocyte Sedimentation Rate (ESR): MedlinePlus Lab Test Information

    Science.gov (United States)

    ... this page: https://medlineplus.gov/labtests/erythrocytesedimentationrateesr.html Erythrocyte Sedimentation Rate (ESR) To use the sharing features ... this page, please enable JavaScript. What is an Erythrocyte Sedimentation Rate (ESR)? An erythrocyte sedimentation rate (ESR) ...

  5. The reduction of starch in finishing diets supplemented with oil does not prevent the accumulation of trans-10 18:1 in lamb meat.

    Science.gov (United States)

    Costa, M; Alves, S P; Francisco, A; Almeida, J; Alfaia, C M; Martins, S V; Prates, J A M; Santos-Silva, J; Doran, O; Bessa, R J B

    2017-08-01

    The experiment was conducted to test the hypothesis that the replacement of cereal with low-starch feed ingredients in lambs' finishing diets supplemented with oils could prevent the accumulation of -10-18:1 in meat. Forty lambs were fed 1 of 4 diets supplemented with soybean oil (5.9%) and fish oil (1%) for 6 wk before slaughter. The control (CON) diet contained 43% barley, and in the other diets, barley was completely replaced by dehydrated citrus pulp (DCP), dehydrated sugar beet pulp (DBP), or soybean hulls (SH). Growth performance, feed intake, and carcass and meat quality traits were analyzed. At slaughter, LM samples were collected for gene expression evaluation, and 3 d after slaughter, LM and subcutaneous (s.c.) fat samples were collected for fatty acid analysis. None of the diets affected meat quality, but the DCP diet reduced ADG ( led to increased a* (redness) and b* (yellowness) in s.c. fat compared with the CON treatment ( 0.05) with treatment and averaged 34.4 g/kg of meat. Diets had no effect ( > 0.05) on SFA, PUFA, and -MUFA sums and on the -6:-3 ratio in both LM and s.c. fat. A lower expression of fatty acid synthase (FASN) was found with the DCP treatment than with the other treatments ( meat and fat.

  6. Apn1 and Apn2 endonucleases prevent accumulation of repair-associated DNA breaks in budding yeast as revealed by direct chromosomal analysis.

    Science.gov (United States)

    Ma, Wenjian; Resnick, Michael A; Gordenin, Dmitry A

    2008-04-01

    Base excision repair (BER) provides relief from many DNA lesions. While BER enzymes have been characterized biochemically, BER functions within cells are much less understood, in part because replication bypass and double-strand break (DSB) repair can also impact resistance to base damage. To investigate BER in vivo, we examined the repair of methyl methanesulfonate (MMS) induced DNA damage in haploid G1 yeast cells, so that replication bypass and recombinational DSB repair cannot occur. Based on the heat-lability of MMS-induced base damage, an assay was developed that monitors secondary breaks in full-length yeast chromosomes where closely spaced breaks yield DSBs that are observed by pulsed-field gel electrophoresis. The assay detects damaged bases and abasic (AP) sites as heat-dependent breaks as well as intermediate heat-independent breaks that arise during BER. Using a circular chromosome, lesion frequency and repair kinetics could be easily determined. Monitoring BER in single and multiple glycosylase and AP-endonuclease mutants confirmed that Mag1 is the major enzyme that removes MMS-damaged bases. This approach provided direct physical evidence that Apn1 and Apn2 not only repair cellular base damage but also prevent break accumulation that can result from AP sites being channeled into other BER pathway(s).

  7. Reduced cellular redox status induces 4-hydroxynonenal-mediated caspase 3 activation leading to erythrocyte death during chronic arsenic exposure in rats.

    Science.gov (United States)

    Biswas, Debabrata; Sen, Gargi; Biswas, Tuli

    2010-05-01

    Chronic exposure to arsenic in rats led to gradual accumulation of the toxicant in erythrocytes causing oxidative stress in these cells. 4-Hydroxynonenal (4-HNE), a major aldehyde product of lipid peroxidation, contributed significantly to the cytopathological events observed during oxidative stress in the erythrocytes of exposed rats. 4-HNE triggered death signal cascade that was initiated with the formation of HNE-protein adducts in cytosol. HNE-protein adduct formation resulted in depletion of cytosolic antioxidants followed by increased generation of ROS. Results showed accumulation of hydrogen peroxide (H(2)O(2)) from the early stages of arsenic exposure, while superoxide (O(2)(*-)) and hydroxyl radical ((*)OH) also contributed to the oxidative stress during longer period of exposure. Suppression of antioxidant system coupled with increased generation of ROS eventually led to activation of caspase 3 during arsenic exposure. Attenuation of HNE-mediated activation of caspase 3 in presence of N-acetylcysteine (NAC) indicated the involvement of GSH in the process. Prevention of HNE-mediated degradation of membrane proteins in presence of Z-DEVD-FMK identified caspase 3 as the principal mediator of HNE-induced cellular damage during arsenic exposure. Degradation of band 3 followed by its aggregation on the red cell surface promoted immunologic recognition of redistributed band 3 by autologous IgG with subsequent attachment of C3b. Finally, the formation of C3b-IgG-band 3 immune complex accelerated the elimination of affected cells from circulation and led to the decline of erythrocyte life span during chronic arsenic toxicity. Copyright 2008 Elsevier Inc. All rights reserved.

  8. Invasion of erythrocytes by Babesia bovis

    NARCIS (Netherlands)

    Gaffar, Fasila Razzia

    2004-01-01

    In this thesis we investigated the invasion of erythrocytes taking place during the asexual erythrocytic blood stage of the apicomplexan parasites Babesia bovis parasite. Host cell invasion by apicomplexan parasites is a complex process requiring multiple receptor-ligand interactions, involving

  9. Comparative Erythrocytes Osmotic Fragility Test and some ...

    African Journals Online (AJOL)

    Erythrocytes with HbSS type showed corpuscular haemaglobin concentration that was significantly lower than HbAA and HbAS (p < 0.0001); mean values of HbAA and HbAS did not show any significant difference. In contrast, HbAA erythrocytes showed mean corpuscular volume (MCV) value that was significantly lower ...

  10. Short Communication Erythrocytic parameters as indicators for ...

    African Journals Online (AJOL)

    Short Communication Erythrocytic parameters as indicators for differentiating between the pregnant and pseudopregnant bitches in Nigeria. ... The trend of decrease in PCV and Hb values were not observed in the bitches with pseudopregnancy. This shows that these erythrocytic parameters can be used to detect and ...

  11. Norisoboldine suppresses osteoclast differentiation through preventing the accumulation of TRAF6-TAK1 complexes and activation of MAPKs/NF-κB/c-Fos/NFATc1 Pathways.

    Directory of Open Access Journals (Sweden)

    Zhi-Feng Wei

    Full Text Available Norisoboldine (NOR is the main alkaloid constituent in the dry root of Lindera aggregata (Sims Kosterm. (L. strychnifolia Vill.. As reported previously, orally administered NOR displayed a robust inhibition of joint bone destruction present in both mouse collagen-induced arthritis and rat adjuvant-induced arthritis with lower efficacious doses than that required for ameliorating systemic inflammation. This attracted us to assess the effects of NOR on differentiation and function of osteoclasts, primary effector cells for inflammatory bone destruction, to get insight into its anti-rheumatoid arthritis mechanisms. Both RAW264.7 cells and mouse bone marrow-derived macrophages (BMMs were stimulated with RANKL (100 ng/mL to establish osteoclast differentiation models. ELISA, RT-PCR, gelatin zymography, western blotting, immunoprecipitation and EMSA were used to reveal related signalling pathways. NOR (10 and 30 µM, without significant cytotoxicity, showed significant reduction of the number of osteoclasts and the resorption pit areas, and it targeted osteoclast differentiation at the early stage. In conjunction with the anti-resorption effect of NOR, mRNA levels of cathepsin K and MMP-9 were decreased, and the activity of MMP-9 was attenuated. Furthermore, our mechanistic studies indicated that NOR obviously suppressed the ubiquitination of TRAF6, the accumulation of TRAF6-TAK1 complexes and the activation of ERK and p38 MAPK, and reduced the nuclear translocation of NF-κB-p65 and DNA-binding activity of NF-κB. However, NOR had little effect on expressions of TRAF6 or the phosphorylation and degradation of IκBα. Moreover, NOR markedly inhibited expressions of transcription factor NFATc1, but not c-Fos. Intriguingly, the subsequent nuclear translocations of c-Fos and NFATc1 were substantially down-regulated. Hence, we demonstrated for the first time that preventing the differentiation and function of osteoclasts at the early stage was an

  12. Catalase and glutathione peroxidase are equally active in detoxification of hydrogen peroxide in human erythrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Gaetani, G.F.; Galiano, S.; Canepa, L.; Ferraris, A.M.; Kirkman, H.N.

    1989-01-01

    Genetic deficiencies of glucose-6-phosphate dehydrogenase (G6PD) and NADPH predispose affected erythrocytes to destruction from peroxides. Conversely, genetic deficiencies of catalase do not predispose affected erythrocytes to peroxide-induced destruction. These observations have served to strengthen the assumption that the NADPH/glutathione/glutathione peroxidase pathway is the principal means for disposal of H/sub 2/O/sub 2/ in human erythrocytes. Recently, however, mammalian catalase was found to have tightly bound NADPH and to require NADPH for the prevention and reversal of inactivation by its toxic substrate (H/sub 2/O/sub 2/). Since both catalase and the glutathione pathway are dependent on NADPH for function, this finding raises the possibility that both mechanisms destroy H/sub 2/O/sub 2/ in human erythrocytes. A comparison of normal and acatalasemic erythrocytes in the present study indicated that catalase accounts for more than half of the destruction of H/sub 2/O/sub 2/ when H/sub 2/O/sub 2/ is generated at a rate comparable to that which leads to hemolysis in G6PD- deficient erythrocytes.

  13. Micronucleated Erythrocytes in Newborn Rats Exposed to Raltegravir Placental Transfer

    Directory of Open Access Journals (Sweden)

    Blanca Miriam Torres-Mendoza

    2014-01-01

    Full Text Available The use of raltegravir in treating HIV/AIDS has been proposed due to its effectiveness in suppressing high loads of HIV RNA in pregnant women, thus preventing infection of the fetus. However, administration of raltegravir during pregnancy produces a compound which is transferred to high concentrations to the offspring. The objective of this study is to evaluate the transplacental genotoxic effect of raltegravir in newborn rats. We evaluated the number of micronucleated erythrocytes (MNE, micronucleated polychromatic erythrocytes (MNPCE, and polychromatic erythrocytes (PCE in the peripheral blood samples of the offspring of Wistar rats treated 6 days before birth with oral administration of raltegravir. The animals were randomly assigned to five groups as follows: raltegravir at doses of 15, 30, or 60 mg/day, cyclophosphamide 10 mg/kg (positive control, or 0.5 ml of sterile water (negative control. In addition, the effect of these drugs on the weight and height of newborns was assessed. There were no differences in the number of MNE, MNPCE, and PCE, and a slight decrease in the weight and height was observed in the offspring of the rat mothers treated with raltegravir. Genotoxicity studies are required in pregnant women to determine the risk of using raltegravir to the fetuses.

  14. Biophotonics of the interaction of low-intensity laser radiation with blood erythrocytes

    Science.gov (United States)

    Asimov, M. M.; Asimov, R. M.; Batyan, A. N.; Trusevich, M. O.; Rubinov, A. N.

    2013-06-01

    We have studied experimentally how optical radiation affects the neutralization of the toxic action of heavy metals and harmful chemical compounds (ecotoxicants) on the oxygen-transport function of blood erythrocytes. It has been found that the optical radiation has a stabilizing effect and prevents lowering the erythrocyte concentration in the presence of phenol and heavy metals in blood. We have studied the neutralization efficiency of the toxic action of ecotoxicants in relation to the laser irradiation time. The obtained data on the effect of the laser radiation on the thermal denaturation of hemoglobin and erythrocytes yield the scientific substantiation to the development of the optical method for the use in medicine upon drawing and conserving donor blood. We have shown that the obtained data can be used in medicine for improving the reliability of conditions of conservation and storage of donor blood, as well as for preventing the toxic action of harmful chemical compounds in the environment.

  15. Application of Mammalian Erythrocytes as Indicators for Newcastle ...

    African Journals Online (AJOL)

    In this study, the potential of heterologous erythrocyte indicator systems for detecting Newcastle Disease (ND) antibodies was investigated using donkey, horse, dog and pig erythrocytes while guinea pig erythrocyte served as the control for comparison. Previous research had shown that guinea pig erythrocyte is useful as ...

  16. [Lysophosphatidic acid and human erythrocyte aggregation].

    Science.gov (United States)

    Sheremet'ev, Iu A; Popovicheva, A N; Levin, G Ia

    2014-01-01

    The effects of lysophosphatidic acid on the morphology and aggregation of human erythrocytes has been studied. Morphology of erythrocytes and their aggregates were studied by light microscopy. It has been shown that lysophosphatidic acid changes the shape of red blood cells: diskocyte become echinocytes. Aggregation of red blood cells (rouleaux) was significantly reduced in autoplasma. At the same time there is a strong aggregation of echinocytes. This was accompanied by the formation of microvesicles. Adding normal plasma to echinocytes restores shape and aggregation of red blood cells consisting of "rouleaux". A possible mechanism of action of lysophosphatidic acid on erythrocytes is discussed.

  17. Prevention

    Science.gov (United States)

    Kerry Britton; Barbara Illman; Gary Man

    2010-01-01

    Prevention is considered the most cost-effective element of the Forest Service Invasive Species Strategy (USDA Forest Service 2004). What makes prevention difficult is the desire to maximize free trade and the resulting benefits to society while, at the same time, protecting natural resources. The role of science is to first identify which commodities pose an...

  18. Prevention

    DEFF Research Database (Denmark)

    Halken, S; Høst, A

    2001-01-01

    , breastfeeding should be encouraged for 4-6 months. In high-risk infants a documented extensively hydrolysed formula is recommended if exclusive breastfeeding is not possible for the first 4 months of life. There is no evidence for preventive dietary intervention neither during pregnancy nor lactation....... Preventive dietary restrictions after the age of 4-6 months are not scientifically documented....

  19. Erythrocyte membrane fluidity and indices of plasmatic oxidative damage after acute physical exercise in humans.

    Science.gov (United States)

    Berzosa, C; Gómez-Trullén, E M; Piedrafita, E; Cebrián, I; Martínez-Ballarín, E; Miana-Mena, F J; Fuentes-Broto, L; García, J J

    2011-06-01

    Optimal levels of membrane fluidity are essential for numerous cell functions including cell growth, solute transport and signal transduction. Since exercise enhances free radical production, our aim was to evaluate in healthy male subjects the effects of an acute bout of maximal and submaximal exercise on the erythrocyte membrane fluidity and its possible relation to the oxidative damage overproduction due to exercise. Subjects (n = 34) performed three cycloergometric tests: a continuous progressive exercise, a strenuous exercise until exhaustion and an acute bout of exercise at an intensity corresponding to 70% of maximal work capacity for 30 min. Venous blood samples were collected before and immediately after these exercises. Erythrocyte membrane fluidity was assessed by fluorescence spectroscopy. Plasma malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA) concentrations and carbonyl content of plasmatic proteins were used as an index of lipid and protein oxidation, respectively. Exercise produced a dramatic drop in the erythrocyte membrane fluidity as compared to resting time, but this was not accompanied by significant changes in the plasmatic MDA and 4-HDA concentrations. The highest erythrocyte membrane rigidity was detected immediately after strenuous exercise until exhaustion was performed. Protein carbonyl levels were higher after exhaustive exercises than at rest. Continuous progressive and strenuous exercises until exhaustion, but not submaximal workload, resulted in a significant enhanced accumulation of carbonylated proteins in the plasma. These findings are consistent with the idea that exercise exaggerates oxidative damage, which may contribute, at least partially, to explain the rigidity in the membrane of the erythrocytes due to acute exercise.

  20. Prevention

    Science.gov (United States)

    ... Tips Latest Research Getting More Help Related Topics Cancer COPD Dementia Depression Diabetes Drug and Substance Abuse Falls Prevention Hearing Loss Heart Attack High Blood Pressure Nutrition Osteoporosis Shingles Skin Cancer Related News Quitting Smoking, ...

  1. Induction of Suicidal Erythrocyte Death by Nelfinavir

    Directory of Open Access Journals (Sweden)

    Rosi Bissinger

    2015-05-01

    Full Text Available The HIV protease inhibitor, nelfinavir, primarily used for the treatment of HIV infections, has later been shown to be effective in various infectious diseases including malaria. Nelfinavir may trigger mitochondria-independent cell death. Erythrocytes may undergo eryptosis, a mitochondria-independent suicidal cell death characterized by cell shrinkage and phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include oxidative stress and increase of cytosolic Ca2+-activity ([Ca2+]i. During malaria, accelerated death of infected erythrocytes may decrease parasitemia and thus favorably influence the clinical course of the disease. In the present study, phosphatidylserine abundance at the cell surface was estimated from annexin V binding, cell volume from forward scatter, reactive oxidant species (ROS from 2',7'-dichlorodihydrofluorescein diacetate (DCFDA fluorescence, and [Ca2+]i from Fluo3-fluorescence. A 48 h treatment of human erythrocytes with nelfinavir significantly increased the percentage of annexin-V-binding cells (≥5µg/mL, significantly decreased forward scatter (≥2.5µg/mL, significantly increased ROS abundance (10 µg/mL, and significantly increased [Ca2+]i (≥5 µg/mL. The up-regulation of annexin-V-binding following nelfinavir treatment was significantly blunted, but not abolished by either addition of the antioxidant N-acetylcysteine (1 mM or removal of extracellular Ca2+. In conclusion, exposure of erythrocytes to nelfinavir induces oxidative stress and Ca2+ entry, thus leading to suicidal erythrocyte death characterized by erythrocyte shrinkage and erythrocyte membrane scrambling.

  2. Stimulation of Erythrocyte Death by Phloretin

    Directory of Open Access Journals (Sweden)

    Rosi Bissinger

    2014-12-01

    Full Text Available Background: Phloretin, a natural component of apples, pears and strawberries, has previously been shown to stimulate apoptosis of nucleated cells. Erythrocytes may similarly enter suicidal death or eryptosis, which is characterized by cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane with phosphatidylserine translocation to the erythrocyte surface. Stimulators of eryptosis include increase of cytosolic Ca2+-activity ([Ca2+]i, ceramide, ATP depletion, and activation of protein kinase C (PKC as well as p38 mitogen activated protein kinase (p38 kinase. Methods: Phosphatidylserine exposure at the cell surface was estimated from annexin V binding, cell volume from forward scatter, [Ca2+]i from Fluo3-fluorescence, and ceramide abundance from binding of specific antibodies. Results: A 48 h exposure of human erythrocytes to phloretin significantly increased the percentage of annexin-V-binding cells (≥100 µM without significantly influencing forward scatter. Phloretin did not significantly modify [Ca2+]i and the stimulation of annexin-V-binding by phloretin (300 µM did not require presence of extracellular Ca2+. Phloretin did not significantly modify erythrocyte ATP levels, and the effect of phloretin on annexin-V-binding was not significantly altered by PKC inhibitor staurosporine (1 µM or p38 kinase inhibitor SB2203580 (2 µM. However, phloretin significantly increased the ceramide abundance at the cell surface. Conclusions: Phloretin stimulates phospholipid scrambling of the erythrocyte cell membrane, an effect at least partially due to up-regulation of ceramide abundance.

  3. Bile Acid-Induced Suicidal Erythrocyte Death

    Directory of Open Access Journals (Sweden)

    Elisabeth Lang

    2016-04-01

    Full Text Available Background/Aims: In nucleated cells, bile acids may activate cation channels subsequently leading to entry of Ca2+. In erythrocytes, increase of cytosolic Ca2+ activity triggers eryptosis, the suicidal death of erythrocytes characterized by phosphatidylserine exposure at the cell surface and cell shrinkage. Eryptosis is triggered by bile duct ligation, an effect partially attributed to conjugated bilirubin. The present study explored, whether bile acids may stimulate eryptosis. Methods: Phosphatidylserine exposing erythrocytes have been identified utilizing annexin V binding, cell volume estimated from forward scatter, cytosolic Ca2+ activity determined using Fluo-3 fluorescence, and ceramide abundance at the erythrocyte surface utilizing specific antibodies. Results: The exposure of human erythrocytes to glycochenodesoxycholic (GCDC and taurochenodesoxycholic (TCDC acid was followed by a significant decrease of forward scatter and significant increase of Fluo-3 fluorescence, ceramide abundance as well as annexin V binding. The effect on annexin V binding was significantly blunted, but not abolished by removal of extracellular Ca2+. Conclusion: Bile acids stimulate suicidal cell death, an effect paralleled by and in part due to Ca2+ entry and ceramide. The bile acid induced eryptosis may in turn lead to accelerated clearance of circulating erythrocytes and, thus, may contribute to anemia in cholestatic patients.

  4. Characterization of carrier erythrocytes for biosensing applications

    Science.gov (United States)

    Bustamante López, Sandra C.; Meissner, Kenith E.

    2017-09-01

    Erythrocyte abundance, mobility, and carrying capacity make them attractive as a platform for blood analyte sensing as well as for drug delivery. Sensor-loaded erythrocytes, dubbed erythrosensors, could be reinfused into the bloodstream, excited noninvasively through the skin, and used to provide measurement of analyte levels in the bloodstream. Several techniques to load erythrocytes, thus creating carrier erythrocytes, exist. However, their cellular characteristics remain largely unstudied. Changes in cellular characteristics lead to removal from the bloodstream. We hypothesize that erythrosensors need to maintain native erythrocytes' (NEs) characteristics to serve as a long-term sensing platform. Here, we investigate two loading techniques and the properties of the resulting erythrosensors. For loading, hypotonic dilution requires a hypotonic solution while electroporation relies on electrical pulses to perforate the erythrocyte membrane. We analyze the resulting erythrosensor signal, size, morphology, and hemoglobin content. Although the resulting erythrosensors exhibit morphological changes, their size was comparable with NEs. The hypotonic dilution technique was found to load erythrosensors much more efficiently than electroporation, and the sensors were loaded throughout the volume of the erythrosensors. Finally, both techniques resulted in significant loss of hemoglobin. This study points to the need for continued development of loading techniques that better preserve NE characteristics.

  5. The Effect of Covalently-Attached ATRP-Synthesized Polymers on Membrane Stability and Cytoprotection in Human Erythrocytes.

    Science.gov (United States)

    Clafshenkel, William P; Murata, Hironobu; Andersen, Jill; Creeger, Yehuda; Koepsel, Richard R; Russell, Alan J

    2016-01-01

    Erythrocytes have been described as advantageous drug delivery vehicles. In order to ensure an adequate circulation half-life, erythrocytes may benefit from protective enhancements that maintain membrane integrity and neutralize oxidative damage of membrane proteins that otherwise facilitate their premature clearance from circulation. Surface modification of erythrocytes using rationally designed polymers, synthesized via atom-transfer radical polymerization (ATRP), may further expand the field of membrane-engineered red blood cells. This study describes the fate of ATRP-synthesized polymers that were covalently attached to human erythrocytes as well as the effect of membrane engineering on cell stability under physiological and oxidative conditions in vitro. The biocompatible, membrane-reactive polymers were homogenously retained on the periphery of modified erythrocytes for at least 24 hours. Membrane engineering stabilized the erythrocyte membrane and effectively neutralized oxidative species, even in the absence of free-radical scavenger-containing polymers. The targeted functionalization of Band 3 protein by NHS-pDMAA-Cy3 polymers stabilized its monomeric form preventing aggregation in the presence of the crosslinking reagent, bis(sulfosuccinimidyl)suberate (BS3). A free radical scavenging polymer, NHS-pDMAA-TEMPO˙, provided additional protection of surface modified erythrocytes in an in vitro model of oxidative stress. Preserving or augmenting cytoprotective mechanisms that extend circulation half-life is an important consideration for the use of red blood cells for drug delivery in various pathologies, as they are likely to encounter areas of imbalanced oxidative stress as they circuit the vascular system.

  6. The Effect of Covalently-Attached ATRP-Synthesized Polymers on Membrane Stability and Cytoprotection in Human Erythrocytes

    Science.gov (United States)

    Clafshenkel, William P.; Murata, Hironobu; Andersen, Jill; Creeger, Yehuda; Russell, Alan J.

    2016-01-01

    Erythrocytes have been described as advantageous drug delivery vehicles. In order to ensure an adequate circulation half-life, erythrocytes may benefit from protective enhancements that maintain membrane integrity and neutralize oxidative damage of membrane proteins that otherwise facilitate their premature clearance from circulation. Surface modification of erythrocytes using rationally designed polymers, synthesized via atom-transfer radical polymerization (ATRP), may further expand the field of membrane-engineered red blood cells. This study describes the fate of ATRP-synthesized polymers that were covalently attached to human erythrocytes as well as the effect of membrane engineering on cell stability under physiological and oxidative conditions in vitro. The biocompatible, membrane-reactive polymers were homogenously retained on the periphery of modified erythrocytes for at least 24 hours. Membrane engineering stabilized the erythrocyte membrane and effectively neutralized oxidative species, even in the absence of free-radical scavenger-containing polymers. The targeted functionalization of Band 3 protein by NHS-pDMAA-Cy3 polymers stabilized its monomeric form preventing aggregation in the presence of the crosslinking reagent, bis(sulfosuccinimidyl)suberate (BS3). A free radical scavenging polymer, NHS-pDMAA-TEMPO˙, provided additional protection of surface modified erythrocytes in an in vitro model of oxidative stress. Preserving or augmenting cytoprotective mechanisms that extend circulation half-life is an important consideration for the use of red blood cells for drug delivery in various pathologies, as they are likely to encounter areas of imbalanced oxidative stress as they circuit the vascular system. PMID:27331401

  7. Altitude Acclimatization and Blood Volume: Effects of Exogenous Erythrocyte Volume Expansion

    National Research Council Canada - National Science Library

    Sawka, M

    1996-01-01

    ...: (a) altitude acclimatization effects on erythrocyte volume and plasma volume; (b) if exogenous erythrocyte volume expansion alters subsequent erythrocyte volume and plasma volume adaptations; (c...

  8. Effects of Long-Term Space Flight on Erythrocytes and Oxidative Stress of Rodents

    Science.gov (United States)

    Rizzo, Angela Maria; Corsetto, Paola Antonia; Montorfano, Gigliola; Milani, Simona; Zava, Stefania; Tavella, Sara; Cancedda, Ranieri; Berra, Bruno

    2012-01-01

    Erythrocyte and hemoglobin losses have been frequently observed in humans during space missions; these observations have been designated as “space anemia”. Erythrocytes exposed to microgravity have a modified rheology and undergo hemolysis to a greater extent. Cell membrane composition plays an important role in determining erythrocyte resistance to mechanical stress and it is well known that membrane composition might be influenced by external events, such as hypothermia, hypoxia or gravitational strength variations. Moreover, an altered cell membrane composition, in particular in fatty acids, can cause a greater sensitivity to peroxidative stress, with increase in membrane fragility. Solar radiation or low wavelength electromagnetic radiations (such as gamma rays) from the Earth or the space environment can split water to generate the hydroxyl radical, very reactive at the site of its formation, which can initiate chain reactions leading to lipid peroxidation. These reactive free radicals can react with the non-radical molecules, leading to oxidative damage of lipids, proteins and DNA, etiologically associated with various diseases and morbidities such as cancer, cell degeneration, and inflammation. Indeed, radiation constitutes on of the most important hazard for humans during long-term space flights. With this background, we participated to the MDS tissue-sharing program performing analyses on mice erythrocytes flown on the ISS from August to November 2009. Our results indicate that space flight induced modifications in cell membrane composition and increase of lipid peroxidation products, in mouse erythrocytes. Moreover, antioxidant defenses in the flight erythrocytes were induced, with a significant increase of glutathione content as compared to both vivarium and ground control erythrocytes. Nonetheless, this induction was not sufficient to prevent damages caused by oxidative stress. Future experiments should provide information helpful to reduce the

  9. Effects of long-term space flight on erythrocytes and oxidative stress of rodents.

    Directory of Open Access Journals (Sweden)

    Angela Maria Rizzo

    Full Text Available Erythrocyte and hemoglobin losses have been frequently observed in humans during space missions; these observations have been designated as "space anemia". Erythrocytes exposed to microgravity have a modified rheology and undergo hemolysis to a greater extent. Cell membrane composition plays an important role in determining erythrocyte resistance to mechanical stress and it is well known that membrane composition might be influenced by external events, such as hypothermia, hypoxia or gravitational strength variations. Moreover, an altered cell membrane composition, in particular in fatty acids, can cause a greater sensitivity to peroxidative stress, with increase in membrane fragility. Solar radiation or low wavelength electromagnetic radiations (such as gamma rays from the Earth or the space environment can split water to generate the hydroxyl radical, very reactive at the site of its formation, which can initiate chain reactions leading to lipid peroxidation. These reactive free radicals can react with the non-radical molecules, leading to oxidative damage of lipids, proteins and DNA, etiologically associated with various diseases and morbidities such as cancer, cell degeneration, and inflammation. Indeed, radiation constitutes on of the most important hazard for humans during long-term space flights. With this background, we participated to the MDS tissue-sharing program performing analyses on mice erythrocytes flown on the ISS from August to November 2009. Our results indicate that space flight induced modifications in cell membrane composition and increase of lipid peroxidation products, in mouse erythrocytes. Moreover, antioxidant defenses in the flight erythrocytes were induced, with a significant increase of glutathione content as compared to both vivarium and ground control erythrocytes. Nonetheless, this induction was not sufficient to prevent damages caused by oxidative stress. Future experiments should provide information helpful to

  10. Effects of high dietary fluorine on erythrocytes and erythrocyte immune adherence function in broiler chickens.

    Science.gov (United States)

    Deng, Yubing; Cui, Hengmin; Peng, Xi; Fang, Jing; Zuo, Zhicai; Deng, Junliang; Luo, Qin

    2013-11-01

    Fluoride can exert toxic effects on soft tissues, giving rise to a broad array of symptoms and pathological changes. The aim of this study was to investigate on erythrocytes and erythrocyte immune adherence function in broiler chickens fed with high fluorine (F) diets by measuring the total erythrocyte count (TEC), the contents of hemoglobin (Hb), packed cell volumn (PCV), erythrocyte osmotic fragility (EOF), erythrocyte C3b receptor rosette rate (E-C3bRR), and erythrocyte immune complex rosette rate (E-ICRR). A total of 280 1-day-old healthy avian broiler chickens were randomly allotted into four equal groups of 70 birds each and fed with a corn-soybean basal diet containing 22.6 mg F/kg (control group) or same basal diets supplemented with 400, 800, and 1,200 mg F/kg (high F groups I, II, and III) in the form of sodium fluoride for 42 days. Blood samples were collected for the abovementioned parameters analysis at 14, 28, and 42 days of age during the experiment. The experimental results indicated that TEC, Hb, and PCV were significantly lower (p erythrocyte membrane, the transport capacity of oxygen and carbon dioxide, and erythrocyte immune adherence function in broiler chickens.

  11. Patients with rheumatoid arthritis treated with methotrexate (MTX): concentrations of steady-state erythrocyte MTX correlate to plasma concentrations and clinical efficacy

    DEFF Research Database (Denmark)

    Hornung, N.; Ellingsen, T.; Attermann, J.

    2008-01-01

    OBJECTIVE: To investigate the accumulation of methotrexate (MTX) in circulating erythrocytes and the association with pharmacokinetic variables, weekly dose, and clinical efficacy in 2 cohorts of patients with chronic active rheumatoid arthritis (RA) undergoing MTX monotherapy. METHODS: Seventy......-six patients with RA were included in this open prospective study: 40 were included before initiation of MTX therapy. Laboratory analyses, intracellular MTX concentrations in erythrocytes (Ery-MTX), and clinical examinations including toxicity data were performed prospectively for 52 weeks. Plasma...

  12. Prevention

    Science.gov (United States)

    ... Protection Equipment (PPE) Sequence for Putting on Personal Protection Equipment (PPE) [PDF – 2.85MB] Select Your PPE Equipment Combination Guidance ... PDF, DOC, PPT, MPEG) on this site? Adobe PDF file Microsoft PowerPoint file Microsoft Word ... last updated: May 11, 2015 Content Source: Centers for Disease Control and Prevention National Center ...

  13. ASSESSMENT OF FREQUENCY OF ALLOIMMUNIZATION AND ERYTHROCYTE AUTOIMMUNIZATION IN TRANSFUSION DEPENDENT THALASSEMIA PATIENTS

    Directory of Open Access Journals (Sweden)

    S. Ansari

    2008-05-01

    Full Text Available Life-long red blood transfusion remains the main treatment for severe thalassemia. The development of hemolytic alloantibodies and erythrocyte autoantibodies complicated transfusion therapy in thalassemia patients. The frequency causes and prevention of this phenomenon among 80 transfused thalassemia patients were evaluated in Ali Asghar Children's Hospital during 1998-2004 in a cross-sectional study. In our study the mean age at the initiation of transfusion was 1.7 years (SD = 1.94 and mean interval of transfusion 33.73 day (SD = 20.74. Autoimmunization in 15 patients was positive and 8 patients had hemolytic reaction in transfusion. Our data show that alloimmunization to minor erythrocyte antigens and erythrocyte autoimmunization of significant clinical variables, are frequent findings in transfused thalassemia patients. However data suggest that prevalence of immunization in our patients is less than other Asian countries.

  14. HEMOLYSIS OF RABBIT ERYTHROCYTES BY PURIFIED STAPHYLOCOCCAL ALPHA-TOXIN III.

    Science.gov (United States)

    Madoff, Morton A.; Cooper, Louis Z.; Weinstein, Louis

    1964-01-01

    Madoff, Morton A. (New England Center Hospital, Boston, Mass.), Louis Z. Cooper, and Louis Weinstein. Hemolysis of rabbit erythrocytes by purified staphylococcal alpha-toxin. III. Potassium release. J. Bacteriol. 87:145–149. 1964.—The reaction between staphylococcal alpha-toxin and erythrocytes was characterized by rapid release of K+ from the cells, early in the prelytic period; 50 to 75% of this loss occurred before leakage of hemoglobin was detectable. The addition of specific antitoxin early enough in the reaction to inhibit gross hemolysis also inhibited cation release. The presence of sucrose or polyethylene glycol prevented hemoglobin release, but was without effect on K+ leak. These observations suggest that K+ loss is a more specific indication of the progress of the reaction between alpha-toxin and erythrocytes than is the release of hemoglobin. PMID:14102847

  15. In Vitro Sensitization of Erythrocytes to Programmed Cell Death Following Baicalein Treatment

    Directory of Open Access Journals (Sweden)

    Rosi Bissinger

    2014-09-01

    Full Text Available The polyphenolic flavonoid Baicalein has been shown to trigger suicidal death or apoptosis of tumor cells and is thus considered for the prevention and treatment of malignancy. Similar to apoptosis of nucleated cells, erythrocytes may enter eryptosis, the suicidal erythrocyte death characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Stimulators of eryptosis include increase of cytosolic Ca2+-activity ([Ca2+]i and ceramide. The present study explored whether Baicalein stimulates eryptosis. To this end, forward scatter was taken for measurement of cell volume, annexin-V-binding for phosphatidylserine-exposure, Fluo3 fluorescence for [Ca2+]i and fluorescent antibodies for ceramide abundance. As a result, a 48 h exposure of human erythrocytes to Baicalein was followed by significant decrease of forward scatter (≥10 µM, significant increase of the percentage of annexin-V-binding cells (≥25 µM, significant increase of [Ca2+]i (50 µM and significant increase of ceramide abundance (50 µM. The effect of Baicalein (50 µM on annexin-V-binding was significantly blunted but not abrogated by removal of extracellular Ca2+. In conclusion, at the concentrations employed, Baicalein stimulates suicidal erythrocyte death or eryptosis, an effect at least in part due to the combined effects of Ca2+ entry and ceramide formation.

  16. Biological activity of blackcurrant Extracts (Ribes nigrum L.) in relation to erythrocyte membranes.

    Science.gov (United States)

    Bonarska-Kujawa, Dorota; Cyboran, Sylwia; Żyłka, Romuald; Oszmiański, Jan; Kleszczyńska, Halina

    2014-01-01

    Compounds contained in fruits and leaves of blackcurrant (Ribes nigrum L.) are known as agents acting preventively and therapeutically on the organism. The HPLC analysis showed they are rich in polyphenol anthocyanins in fruits and flavonoids in leaves, that have antioxidant activity and are beneficial for health. The aim of the research was to determine the effect of blackcurrant fruit and leaf extracts on the physical properties of the erythrocyte membranes and assess their antioxidant properties. The effect of the extracts on osmotic resistance, shape of erythrocytes and hemolytic and antioxidant activity of the extracts were examined with spectrophotometric methods. The FTIR investigation showed that extracts modify the erythrocyte membrane and protect it against free radicals induced by UV radiation. The results show that the extracts do not induce hemolysis and even protect erythrocytes against the harmful action of UVC radiation, while slightly strengthening the membrane and inducing echinocytes. The compounds contained in the extracts do not penetrate into the hydrophobic region, but bind to the membrane surface inducing small changes in the packing arrangement of the polar head groups of membrane lipids. The extracts have a high antioxidant activity. Their presence on the surface of the erythrocyte membrane entails protection against free radicals.

  17. Hydrochlorothiazide, but not Candesartan, Aggravates Insulin Resistance and Causes Visceral and Hepatic Fat Accumulation: The Mechanisms for the Diabetes Preventing Effect of Candesartan (MEDICA) Study

    National Research Council Canada - National Science Library

    Eriksson, Jan W; Jansson, Per-Anders; Carlberg, Bo; Hägg, Anders; Kurland, Lisa; Svensson, Maria K; Ahlström, Håkan; Ström, Conny; Lönn, Lars; Öjbrandt, Kristina; Johansson, Lars; Lind, Lars

    2008-01-01

    .... The Mechanisms for the Diabetes Preventing Effect of Candesartan Study addressed insulin action and secretion and body fat distribution after treatment with candesartan, hydrochlorothiazide, and placebo...

  18. Edelfosine Induced Suicidal Death of Human Erythrocytes

    Directory of Open Access Journals (Sweden)

    Marilena Briglia

    2015-11-01

    Full Text Available Background/Aims: The anti-inflammatory, anti-autoimmune, antiparasitic, and anti-viral ether phospholipid edelfosine (1-O-octadecyl-2-O-methylglycero-3-phosphocholine stimulates apoptosis of tumor cells and is thus considered for the treatment of malignancy. Similar to apoptosis of nucleated cells, erythrocytes may enter eryptosis, the suicidal erythrocyte death characterized by cell shrinkage and phospholipid scrambling of the cell membrane with phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include Ca2+ entry with increase of cytosolic Ca2+ activity ([Ca2+]i and oxidative stress. The present study explored, whether and how edelfosine induces eryptosis. Methods: Flow cytometry and photometry, respectively, were employed to estimate phosphatidylserine exposure at the cell surface from annexin-V-binding, cell volume from forward scatter, hemolysis from hemoglobin release, [Ca2+]i from Fluo3-fluorescence, and abundance of reactive oxygen species (ROS from 2',7'-dichlorodihydrofluorescein diacetate (DCFDA fluorescence. Results: A 6 hours exposure of human erythrocytes to edelfosine (5 µM significantly increased the percentage of annexin-V-binding cells, significantly decreased forward scatter, and significantly increased Fluo3-fluorescence, but did not significantly modify DCFDA fluorescence. The effect of edelfosine on annexin-V-binding was significantly blunted, but not abolished by removal of extracellular Ca2+. Conclusions: Edelfosine triggers cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect in part due to stimulation of Ca2+ entry.

  19. Patulin-Induced Suicidal Erythrocyte Death

    Directory of Open Access Journals (Sweden)

    Adrian Lupescu

    2013-07-01

    Full Text Available Background: Patulin, the most common mycotoxin in apples and apple-derived products, triggers apoptosis and has thus been considered for the treatment of cancer. Similar to apoptosis of nucleated cells, erythrocytes may enter suicidal death or eryptosis, which is characterized by cell shrinkage and by cell membrane scrambling leading to phosphatidylserine-exposure at the erythrocyte surface. Stimulators of eryptosis include increase of cytosolic Ca2+-activity ([Ca2+]i. The present study explored, whether exposure of human erythrocytes to patulin is followed by eryptosis. Methods: Forward scatter was measured to estimate cell volume, annexin V binding to detect phosphatidylserine-exposure, hemoglobin release to quantify hemolysis, and Fluo3-fuorescence to determine [Ca2+]i. Results: A 48 h exposure to patulin significantly increased [Ca2+]I (5 µM, significantly decreased forward scatter (5 µM and significantly increased annexin-V-binding (2.5 µM. Patulin (10 µM induced annexin-V-binding was virtually abrogated by removal of extracellular Ca2+. Conclusion: Patulin stimulates Ca2+ entry into erythrocytes, an effect triggering suicidal erythrocyte death or eryptosis.

  20. Patulin-induced suicidal erythrocyte death.

    Science.gov (United States)

    Lupescu, Adrian; Jilani, Kashif; Zbidah, Mohanad; Lang, Florian

    2013-01-01

    Patulin, the most common mycotoxin in apples and apple-derived products, triggers apoptosis and has thus been considered for the treatment of cancer. Similar to apoptosis of nucleated cells, erythrocytes may enter suicidal death or eryptosis, which is characterized by cell shrinkage and by cell membrane scrambling leading to phosphatidylserine-exposure at the erythrocyte surface. Stimulators of eryptosis include increase of cytosolic Ca(2+)-activity ([Ca(2+)]i). The present study explored, whether exposure of human erythrocytes to patulin is followed by eryptosis. Forward scatter was measured to estimate cell volume, annexin V binding to detect phosphatidylserine-exposure, hemoglobin release to quantify hemolysis, and Fluo3-fuorescence to determine [Ca(2+)]i. A 48 h exposure to patulin significantly increased [Ca(2+)]I (5 µM), significantly decreased forward scatter (5 µM) and significantly increased annexin-V-binding (2.5 µM). Patulin (10 µM) induced annexin-V-binding was virtually abrogated by removal of extracellular Ca(2+). Patulin stimulates Ca(2+) entry into erythrocytes, an effect triggering suicidal erythrocyte death or eryptosis. Copyright © 2013 S. Karger AG, Basel.

  1. Mapping of hemoglobin in erythrocytes and erythrocyte ghosts using two photon excitation fluorescence microscopy

    Science.gov (United States)

    Bukara, Katarina; Jovanić, Svetlana; Drvenica, Ivana T.; Stančić, Ana; Ilić, Vesna; Rabasović, Mihailo D.; Pantelić, Dejan; Jelenković, Branislav; Bugarski, Branko; Krmpot, Aleksandar J.

    2017-02-01

    The present study describes utilization of two photon excitation fluorescence (2PE) microscopy for visualization of the hemoglobin in human and porcine erythrocytes and their empty membranes (i.e., ghosts). High-quality, label- and fixation-free visualization of hemoglobin was achieved at excitation wavelength 730 nm by detecting visible autofluorescence. Localization in the suspension and spatial distribution (i.e., mapping) of residual hemoglobin in erythrocyte ghosts has been resolved by 2PE. Prior to the 2PE mapping, the presence of residual hemoglobin in the bulk suspension of erythrocyte ghosts was confirmed by cyanmethemoglobin assay. 2PE analysis revealed that the distribution of hemoglobin in intact erythrocytes follows the cells' shape. Two types of erythrocytes, human and porcine, characterized with discocyte and echinocyte morphology, respectively, showed significant differences in hemoglobin distribution. The 2PE images have revealed that despite an extensive washing out procedure after gradual hypotonic hemolysis, a certain amount of hemoglobin localized on the intracellular side always remains bound to the membrane and cannot be eliminated. The obtained results open the possibility to use 2PE microscopy to examine hemoglobin distribution in erythrocytes and estimate the purity level of erythrocyte ghosts in biotechnological processes.

  2. Erythrocyte Membrane Failure by Electromechanical Stress

    Directory of Open Access Journals (Sweden)

    E Du

    2018-01-01

    Full Text Available We envision that electrodeformation of biological cells through dielectrophoresis as a new technique to elucidate the mechanistic details underlying membrane failure by electrical and mechanical stresses. Here we demonstrate the full control of cellular uniaxial deformation and tensile recovery in biological cells via amplitude-modified electric field at radio frequency by an interdigitated electrode array in microfluidics. Transient creep and cyclic experiments were performed on individually tracked human erythrocytes. Observations of the viscoelastic-to-viscoplastic deformation behavior and the localized plastic deformations in erythrocyte membranes suggest that electromechanical stress results in irreversible membrane failure. Examples of membrane failure can be separated into different groups according to the loading scenarios: mechanical stiffening, physical damage, morphological transformation from discocyte to echinocyte, and whole cell lysis. These results show that this technique can be potentially utilized to explore membrane failure in erythrocytes affected by other pathophysiological processes.

  3. Saquinavir Induced Suicidal Death of Human Erythrocytes

    Directory of Open Access Journals (Sweden)

    Sabrina Waibel

    2015-11-01

    Full Text Available Background/Aims: The antiretroviral protease inhibitor saquinavir is used for the treatment of HIV infections. Effects of saquinavir include induction of apoptosis, the suicidal death of nucleated cells. Saquinavir treatment may further lead to anemia. In theory, anemia could result from accelerated erythrocyte loss by enhanced suicidal erythrocyte death or eryptosis, which is characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Stimulators of eryptosis include Ca2+ entry with increase of cytosolic Ca2+ activity ([Ca2+]i, oxidative stress with increase of reactive oxygen species (ROS and ceramide. The present study explored, whether and how saquinavir induces eryptosis. Methods: To this end, flow cytometry was employed to estimate erythrocyte volume from forward scatter, phosphatidylserine exposure at the cell surface from annexin-V-binding, [Ca2+]i from Fluo3-fluorescence, ROS abundance from DCFDA fluorescence and ceramide abundance utilizing specific antibodies. Results: A 48 hours exposure of human erythrocytes to saquinavir significantly decreased forward scatter (≥ 5 µg/ml, significantly increased the percentage of annexin-V-binding cells (≥ 10 µg/ml, significantly increased Fluo3-fluorescence (15 µg/ml, significantly increased DCFDA fluorescence (15 µg/ml, but did not significantly modify ceramide abundance. The effect of saquinavir on annexin-V-binding was significantly blunted, but not abolished by removal of extracellular Ca2+. Conclusions: Saquinavir triggers cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect in part due to stimulation of ROS formation and Ca2+ entry.

  4. Cryo scanning electron microscopy of Plasmodium falciparum-infected erythrocytes

    DEFF Research Database (Denmark)

    Hempel, Casper

    2017-01-01

    Plasmodium falciparum invades erythrocytes as an essential part of their life cycle. While living inside erythrocytes, the parasite remodels the cell's intracellular organization as well as its outer surface. Late trophozoite-stage parasites and schizonts introduce numerous small protrusions...

  5. Lysis of erythrocytes by Trichomonas gallinae.

    Science.gov (United States)

    De Carli, G A; da Silva, A C; Wendorff, A; Rott, M

    1996-01-01

    The hemolytic activity of five live isolates of Trichomonas gallinae was investigated. The isolates were subsequently tested against the erythrocytes of seven adult animal species. Each of the five isolates tested lysed all human blood groups, as well as rabbit, rat, chicken, horse, bovine, and sheep erythrocytes. No hemolysin released by the parasite could be detected. Our preliminary results suggest that the hemolytic activity is not due to the hemolysin release by T. gallinae or to a product of its metabolism. Pretreatment of live trichomonads with concanavalin A reduced levels of hemolysis by 40%.

  6. Erythrocyte sedimentation rate and C-reactive protein.

    Science.gov (United States)

    Harrison, Michael

    2015-06-01

    C-reactive protein is a better indicator of inflammation than the erythrocyte sedimentation rate. It is more sensitive and responds more quickly to changes in the clinical situation. False negative and false positive results are more common when measuring the erythrocyte sedimentation rate. Renal disease, female sex and older age increase the erythrocyte sedimentation rate. The erythrocyte sedimentation rate has value in detecting low-grade bone infection, and in monitoring some patients with systemic lupus erythematosus.

  7. Increased caspase-3 immunoreactivity of erythrocytes in STZ diabetic rats.

    Science.gov (United States)

    Fırat, Uğur; Kaya, Savaş; Cim, Abdullah; Büyükbayram, Hüseyin; Gökalp, Osman; Dal, Mehmet Sinan; Tamer, Mehmet Numan

    2012-01-01

    Eryptosis is a term to define apoptosis of erythrocytes. Oxidative stress and hyperglycemia, both of which exist in the diabetic intravascular environment, can trigger eryptosis of erythrocytes. In this experimental study, it is presented that the majority of erythrocytes shows caspase-3 immunoreactivity in streptozocin- (STZ)-induced diabetic rats. Besides that, caspase-3 positive erythrocytes are aggregated and attached to vascular endothelium. In conclusion, these results may start a debate that eryptosis could have a role in the diabetic complications.

  8. Erythrocyte glutathione levels in lithium-induced hypothyroidism.

    Science.gov (United States)

    Engin, Atilla; Altan, Nilgun; Isik, Erdal

    2005-01-01

    significant difference in the thyroid-stimulating hormone values as well as the red blood cell glutathione contents or superoxide dismutase activities between healthy controls and lithium-treated euthyroid subjects. It is most likely that lithium primarily inhibited hormone production in the thyroid and that this led to a compensatory increase in thyroid-stimulating hormone secretion with a significant decrease in the red blood cell glutathione content. While the red blood cell glutathione content of hypothyroid patients was reduced to 40% of the post-thyroxine level, unchanged superoxide dismutase activity might render the erythrocytes vulnerable to oxidative stress and ultimately haemolysis. Thyroxine replacement during lithium prophylaxis of psychiatric patients is advisable in order to prevent subclinical hypothyroidism and related defects of erythrocyte antioxidant capacity.

  9. Accurate determination of selenium and iron in erythrocytes from ...

    African Journals Online (AJOL)

    Accurate determination of selenium and iron in erythrocytes from Nigeria subjects using INAA. JO Ojo, Jan Kucera. Abstract. Levels of two essential elements playing crucial roles in erythrocyte's structure and functions, iron and selenium, have been carefully determined in 36 erythrocyte samples drawn from two healthy ...

  10. Should erythrocyte destruction in vivo be through phagocytosis alone?

    Indian Academy of Sciences (India)

    did not lower their EDA, strongly suggesting the involvement of non-phagocytic mechanisms in erythrocyte destruction. Assessment of erythrocyte lysis by the chromium release assay of cytotoxicity also provided direct evidence of erythrocyte lysis by leukocytes. T cells appear to be indirectly involved in. EDA associated with.

  11. Paired Chicken and Mammalian Erythrocyte Indicator Systems for ...

    African Journals Online (AJOL)

    Three levels of erythrocytes suspensions, 1.5%, 1% and 0.5% respectively from goat and guinea pig, were compared to conventional 0.5% chicken erythrocytes, in an attempt to investigate the suitability for the two sources of mammalian erythrocytes as indicators for Newcastle disease virus haemagglutination (HA) tests.

  12. 21 CFR 864.6700 - Erythrocyte sedimentation rate test.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Erythrocyte sedimentation rate test. 864.6700... (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6700 Erythrocyte sedimentation rate test. (a) Identification. An erythrocyte sedimentation rate test is a device that measures...

  13. Plasmodium falciparum erythrocyte invasion: combining function with immune evasion.

    Directory of Open Access Journals (Sweden)

    Gavin J Wright

    2014-03-01

    Full Text Available All the symptoms and pathology of malaria are caused by the intraerythrocytic stages of the Plasmodium parasite life cycle. Because Plasmodium parasites cannot replicate outside a host cell, their ability to recognize and invade erythrocytes is an essential step for both parasite survival and malaria pathogenesis. This makes invasion a conceptually attractive vaccine target, especially because it is one of the few stages when the parasite is directly exposed to the host humoral immune system. This apparent vulnerability, however, has been countered by the parasite, which has evolved sophisticated molecular mechanisms to evade the host immune response so that parasites asymptomatically replicate within immune individuals. These mechanisms include the expansion of parasite invasion ligands, resulting in multiple and apparently redundant invasion "pathways", highly polymorphic parasite surface proteins that are immunologically distinct, and parasite proteins which are poorly immunogenic. These formidable defences have so far thwarted attempts to develop an effective blood-stage vaccine, leading many to question whether there really is an exploitable chink in the parasite's immune evasion defences. Here, we review recent advances in the molecular understanding of the P. falciparum erythrocyte invasion field, discuss some of the challenges that have so far prevented the development of blood-stage vaccines, and conclude that the parasite invasion ligand RH5 represents an essential pinch point that might be vulnerable to vaccination.

  14. Protective effect of desloratadine against oxidative stress in human erythrocytes in vitro.

    Science.gov (United States)

    Sadowska-Woda, Izabela; Sychta, Barbara; Rachel, Marta; Bieszczad-Bedrejczuk, Edyta

    2010-09-01

    Desloratadine (DCL) is a non-sedating antihistamine approved for the treatment of allergic rhinitis or chronic idiopathic urticaria. The objective of this study was to evaluate the potential protective effect of DCL against oxidative stress in human erythrocytes in vitro. Human erythrocytes were oxidized by a water-soluble radical generators-2,2' azobis (2-amidinopropane) hydrochloride (AAPH; 20, 50mM) or tert-butyl hydroperoxide (TBHP; 0.5mM) and the protective effects of DCL (2, 5, 7, 10 and 26μM) on selected oxidative stress markers were investigated. Erythrocytes were divided into aliquots. The first aliquot was incubated for 2h at 37°C with AAPH or TBHP. The other test aliquots were preincubated with selected concentrations of DCL for 30min and followed by AAPH or TBHP incubation for 2h. Malondialdehyde (MDA) content, catalase (CAT) and superoxide dismutase (SOD) activities, as well as hemolysis percentage (H) were measured in all erythrocyte samples. The influence of solvent (0.5% ethanol) on the parameters studied was also checked. Pretreatment with DCL (7, 10, 26μM) could prevent TBHP-induced increase in MDA formation in a concentration-dependent manner. DCL has no influence on CAT activity and it significantly enhanced SOD activity compared to AAPH treatment samples at 7, 10, 26μM. DCL (26μM) also reduced the hemolytic effect on erythrocytes when compared to the erythrocytes exposed to oxidants only. These results suggest a beneficial effect of DCL as an antioxidant, which might be an additional explanation of its therapeutic action. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Effects of Red Wine Tannat on Oxidative Stress Induced by Glucose and Fructose in Erythrocytes in Vitro.

    Science.gov (United States)

    Pazzini, Camila Eliza Fernandes; Colpo, Ana Ceolin; Poetini, Márcia Rósula; Pires, Cauê Ferreira; de Camargo, Vanessa Brum; Mendez, Andreas Sebastian Loureiro; Azevedo, Miriane Lucas; Soares, Júlio César Mendes; Folmer, Vanderlei

    2015-01-01

    The literature indicates that red wine presents in its composition several substances that are beneficial to health. This study has investigated the antioxidant effects of Tannat red wine on oxidative stress induced by glucose and fructose in erythrocytes in vitro, with the purpose to determine some of its majoritarian phenolic compounds and its antioxidant capacity. Erythrocytes were incubated using different concentrations of glucose and fructose in the presence or absence of wine. From these erythrocytes were determined the production of thiobarbituric acid reactive species (TBARS), glucose consumption, and osmotic fragility. Moreover, quantification of total phenolic, gallic acid, caffeic acid, epicatechin, resveratrol, and DPPH scavenging activity in wine were also assessed. Red wine showed high levels of polyphenols analyzed, as well as high antioxidant potential. Erythrocytes incubated with glucose and fructose had an increase in lipid peroxidation and this was prevented by the addition of wine. The wine increased glucose uptake into erythrocytes and was able to decrease the osmotic fragility of erythrocytes incubated with fructose. Altogether, these results suggest that wine leads to a reduction of the oxidative stress induced by high concentrations of glucose and fructose.

  16. Effects of Red Wine Tannat on Oxidative Stress Induced by Glucose and Fructose in Erythrocytes in Vitro

    Science.gov (United States)

    Pazzini, Camila Eliza Fernandes; Colpo, Ana Ceolin; Poetini, Márcia Rósula; Pires, Cauê Ferreira; de Camargo, Vanessa Brum; Mendez, Andreas Sebastian Loureiro; Azevedo, Miriane Lucas; Soares, Júlio César Mendes; Folmer, Vanderlei

    2015-01-01

    The literature indicates that red wine presents in its composition several substances that are beneficial to health. This study has investigated the antioxidant effects of Tannat red wine on oxidative stress induced by glucose and fructose in erythrocytes in vitro, with the purpose to determine some of its majoritarian phenolic compounds and its antioxidant capacity. Erythrocytes were incubated using different concentrations of glucose and fructose in the presence or absence of wine. From these erythrocytes were determined the production of thiobarbituric acid reactive species (TBARS), glucose consumption, and osmotic fragility. Moreover, quantification of total phenolic, gallic acid, caffeic acid, epicatechin, resveratrol, and DPPH scavenging activity in wine were also assessed. Red wine showed high levels of polyphenols analyzed, as well as high antioxidant potential. Erythrocytes incubated with glucose and fructose had an increase in lipid peroxidation and this was prevented by the addition of wine. The wine increased glucose uptake into erythrocytes and was able to decrease the osmotic fragility of erythrocytes incubated with fructose. Altogether, these results suggest that wine leads to a reduction of the oxidative stress induced by high concentrations of glucose and fructose. PMID:26078708

  17. Arsenic-induced suicidal erythrocyte death

    Energy Technology Data Exchange (ETDEWEB)

    Mahmud, Hasan; Foeller, Michael; Lang, Florian [University of Tuebingen (Germany). Department of Physiology

    2009-02-15

    Environmental exposure to arsenic has been associated with anemia, which could result from suicidal erythrocyte death or eryptosis, characterized by cell shrinkage and phosphatidylserine exposure at the erythrocyte surface. Eryptosis is triggered by increase in cytosolic Ca{sup 2+} concentration, ceramide and energy depletion. The present experiments explored, whether arsenic stimulates eryptosis. According to annexin V-binding, arsenic trioxide (7{mu}M) within 48 h significantly increased phosphatidylserine exposure of human erythrocytes without inducing hemolysis. According to forward scatter, arsenic trioxide (7{mu}M) significantly decreased cell volume. Moreover, Fluo3-fluorescence showed that arsenic (10 {mu}M) significantly increased cytosolic Ca{sup 2+} concentration. According to binding of respective fluorescent antibodies, arsenic trioxide (10{mu}M) significantly increased ceramide formation. Arsenic (10{mu}M) further lowered the intracellular ATP concentration. Removal of extracellular Ca{sup 2+} or inhibition of the Ca{sup 2+}-permeable cation channels with amiloride blunted the effects of arsenic on annexin V-binding and cell shrinkage. In conclusion, arsenic triggers suicidal erythrocyte death by increasing cytosolic Ca{sup 2+} concentration, by stimulating the formation of ceramide and by decreasing ATP availability. (orig.)

  18. Erythrocyte seditnentation rate in elderly blacks

    African Journals Online (AJOL)

    Abstract This study inv~tigated the erythrocyte sedimen- tation rate (ESR) in an elderly population with the objective of establishing reference ranges and the diagnostic value of the ESR. Elderly blacks were randomly selected frOIn conununities in the. Orange Free State. ESR determinations were done according to the ...

  19. Stimulation of suicidal erythrocyte death by sulforaphane.

    Science.gov (United States)

    Alzoubi, Kousi; Calabrò, Salvatrice; Faggio, Caterina; Lang, Florian

    2015-03-01

    Sulforaphane, an isothiocyanate from cruciferous vegetable, counteracts malignancy. The effect is at least in part due to the stimulation of suicidal death or apoptosis of tumour cells. Mechanisms invoked in sulforaphane-induced apoptosis include mitochondrial depolarization and altered gene expression. Despite the lack of mitochondria and nuclei, erythrocytes may, similar to apoptosis of nucleated cells, enter eryptosis, a suicidal cell death characterized by cell shrinkage and phosphatidylserine translocation to the erythrocyte surface. Stimulators of eryptosis include increase of cytosolic Ca(2+)-activity ([Ca(2+)]i). This study explored whether sulforaphane stimulates eryptosis. Cell volume was estimated from forward scatter, phosphatidylserine exposure at the cell surface from annexin V binding and [Ca(2+)]i from Fluo-3 fluorescence. A 48-hr treatment of human erythrocytes with sulforaphane (50-100 μM) significantly decreased forward scatter, significantly increased the percentage of annexin V binding cells and significantly increased [Ca(2+)]i. The effect of sulforaphane (100 μM) on annexin V binding was significantly blunted but not abrogated by the removal of extracellular Ca(2+). Sulforaphane (100 μM) significantly increased ceramide formation. In conclusion, sulforaphane stimulates suicidal erythrocyte death or eryptosis, an effect at least partially, but not exclusively, due to the stimulation of Ca(2+) entry and ceramide formation. © 2014 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  20. Baseline Haematology and Erythrocyte Morphological Changes of ...

    African Journals Online (AJOL)

    olayemitoyin

    Department of Veterinary Pathology, University of Ibadan. Nigeria Ibadan, Nigeria. Summary: This study evaluates the haematological parameters and the observed erythrocytes morphological changes in dogs raised in Ibadan, Oyo State in the south western part of Nigeria. Blood samples were collected from sixty-four.

  1. Baseline Haematology and Erythrocyte Morphological Changes of ...

    African Journals Online (AJOL)

    Summary: This study evaluates the haematological parameters and the observed erythrocytes morphological changes in dogs raised in Ibadan, Oyo State in the south western part of Nigeria. Blood samples were collected from sixty-four apparently healthy dogs. The haematological parameters of the blood samples ...

  2. Erythrocyte aging in sickle cell disease.

    NARCIS (Netherlands)

    Bosman, G.J.C.G.M.

    2004-01-01

    Physiological removal of old erythrocytes from the circulation by macrophages is initiated by binding of autologous IgG to senescent cell antigen (SCA). SCA is generated from the anion exchanger band 3. This process is accompanied by a number of alterations in the function and structure of band 3.

  3. Effect of Lipophilic Bismuth Nanoparticles on Erythrocytes

    Directory of Open Access Journals (Sweden)

    Rene Hernandez-Delgadillo

    2015-01-01

    Full Text Available Lipophilic bismuth dimercaptopropanol nanoparticles (BisBAL NPs have a very important antimicrobial activity; however their effect on human cells or tissues has not been completely studied. Undesirable effects of bismuth include anemia which could result from suicidal erythrocyte death or eryptosis. The objective of this research was to determine the effect of bismuth dimercaptopropanol nanoparticles on blood cells. The nanoparticles are composed of 53 nm crystallites on average and have a spherical structure, agglomerating into clusters of small nanoparticles. Based on cell viability assays and optical microscopy, cytotoxicity on erythrocytes was observed after growing with 500 and 1000 µM of BisBAL NPs for 24 h. AM Calcein was retained inside erythrocytes when they were exposed to 100 µM (or lower concentrations of BisBAL NPs for 24 h, suggesting the absence of damage in plasmatic membrane. Genotoxic assays revealed no damage to genomic DNA of blood cells after 24 h of exposition to BisBAL NPs. Finally, 100–1000 µM of bismuth nanoparticles promotes apoptosis between blood cells after 24 h of incubation. Hence BisBAL NPs at concentrations lower than 100 µM do not cause damage on blood cells; they could potentially be used by humans without affecting erythrocytes and leukocytes.

  4. Brucella melitensis Invades Murine Erythrocytes during Infection

    Science.gov (United States)

    Vitry, Marie-Alice; Hanot Mambres, Delphine; Deghelt, Michaël; Hack, Katrin; Machelart, Arnaud; Lhomme, Frédéric; Vanderwinden, Jean-Marie; Vermeersch, Marjorie; De Trez, Carl; Pérez-Morga, David; Letesson, Jean-Jacques

    2014-01-01

    Brucella spp. are facultative intracellular Gram-negative coccobacilli responsible for brucellosis, a worldwide zoonosis. We observed that Brucella melitensis is able to persist for several weeks in the blood of intraperitoneally infected mice and that transferred blood at any time point tested is able to induce infection in naive recipient mice. Bacterial persistence in the blood is dramatically impaired by specific antibodies induced following Brucella vaccination. In contrast to Bartonella, the type IV secretion system and flagellar expression are not critically required for the persistence of Brucella in blood. ImageStream analysis of blood cells showed that following a brief extracellular phase, Brucella is associated mainly with the erythrocytes. Examination by confocal microscopy and transmission electron microscopy formally demonstrated that B. melitensis is able to invade erythrocytes in vivo. The bacteria do not seem to multiply in erythrocytes and are found free in the cytoplasm. Our results open up new areas for investigation and should serve in the development of novel strategies for the treatment or prophylaxis of brucellosis. Invasion of erythrocytes could potentially protect the bacterial cells from the host's immune response and hamper antibiotic treatment and suggests possible Brucella transmission by bloodsucking insects in nature. PMID:25001604

  5. The Current Relevance and Applications of Erythrocyte ...

    African Journals Online (AJOL)

    The erythrocyte sedimentation rate (ESR) is a simple and inexpensive laboratory test. It is commonly used to assess the acute phase response. A review of relevant literature was done to evaluate the role of the ESR and its importance in different clinical conditions both inflammatory and non-inflammatory. Despite the critical ...

  6. Changes in Hematological Parameters and Erythrocyte Osmotic ...

    African Journals Online (AJOL)

    The study was aimed at evaluating the changes in haematological parameters and erythrocyte osmotic fragility in lame and aged horses administered with resveratrol supplement (Equithrive joint®). A total of 16 horses of both sexes, aged 18 ± 0.65 and showing lameness grade 3 were used for the study. The horses ...

  7. Electrophoretic mobilities of erythrocytes in various buffers

    Science.gov (United States)

    Plank, L. D.; Kunze, M. E.; Todd, P. W.

    1985-01-01

    The calibration of space flight equipment depends on a source of standard test particles, this test particle of choice is the fixed erythrocyte. Erythrocytes from different species have different electrophoretic mobilities. Electrophoretic mobility depends upon zeta potential, which, in turn depends upon ionic strength. Zeta potential decreases with increasing ionic strength, so cells have high electrophoretic mobility in space electrophoresis buffers than in typical physiological buffers. The electrophoretic mobilities of fixed human, rat, and rabbit erythrocytes in 0.145 M salt and buffers of varying ionic strength, temperature, and composition, to assess the effects of some of the unique combinations used in space buffers were characterized. Several effects were assessed: glycerol or DMSO (dimethylsulfoxide) were considered for use as cryoprotectants. The effect of these substances on erythrocyte electrophoretic mobility was examined. The choice of buffer depended upon cell mobility. Primary experiments with kidney cells established the choice of buffer and cryoprotectant. A nonstandard temperature of EPM in the suitable buffer was determined. A loss of ionic strength control occurs in the course of preparing columns for flight, the effects of small increases in ionic strength over the expected low values need to be evaluated.

  8. Changes in haematology, plasma biochemistry and erythrocyte ...

    African Journals Online (AJOL)

    There was also a stress induced increased heterophil/lymphocyte ratio and the erythrocytes were more fragile in hypotonic solution in birds sampled at 8 weeks. Plasma aspartate transaminase (AST), alanine aminotransferase (ALT) and alkaline phosphate (ALP) increased at 8 weeks, though non-significantly, which might ...

  9. Changes in haematology, plasma biochemistry and erythrocyte ...

    African Journals Online (AJOL)

    olayemitoyin

    Summary: The haematology, plasma biochemistry and erythrocyte osmotic fragility of the Nigerian laughing dove. (Streptopelia senegalensis) were studied after 4 and 8 weeks in captivity. At 8 weeks, there was a normocytic hypochromic anaemia characterized by reduced values for packed cell volume (PCV), red blood cell ...

  10. Erythrocyte survival in sheep exposed to ozone

    Energy Technology Data Exchange (ETDEWEB)

    Moore, G.S.; Calabrese, E.J.; Labato, F.J.

    1981-07-01

    Erythrocyte survival studies in the Dorset ewe using chromium 51 were performed. The purpose of the study was to determine if ozone exposure produces decreased cell survival which may be the result of premature erythrocyte aging. This strain of sheep has an erythrocyte glucose-6-phosphate dehydrogenase (G6PD) activity that is very low, being comparable to human A-variants with G6PD deficiency. Ozone exposure may produce hemolytic effects in G6PD deficients more readily than in erythrocytes with normal activity. A decrease in hematocrit was observed in the ozone exposed groups. With respect to red cell destruction, ozone does not appear to act immediately, but rather there appears to be a delayed effect. At 0.25 ppM ozone, the group reached the 50% remaining level an average of 1 day sooner than the control group. There was no significant difference between control and exposed groups at the 0.50 ppM and 0.70 ppM levels. Also, the results demonstrate a net decrease in hematocrit which is greater for 0.25 ppM ozone than any other exposure level. (RJC)

  11. Telfairia Occidentalis Extract Stabilizes Human Erythrocyte ...

    African Journals Online (AJOL)

    In addition to being a widely consumed vegetable in West Africa, the leaves extract of Telfairia occidentalis is believed to have beneficial health effects and is used in tradomedical preparations. The effect of saline extract of T. occidentalis leaves on sickle and normal erythrocytes membrane stability was investigated. Human ...

  12. The correlation between erythrocyte sedimentation rate and ...

    African Journals Online (AJOL)

    Objective: To evaluate the relative importance of infections as indexed by raised erythrocyte sedimentation rate in the aetiology of benign or so called ethnic leucopaenia in persons of African origin. Method: Raised ESR is indicative of the process of organic disease. We sought the correlation of ESR with the total and ...

  13. Erythrocyte stability, membrane protective and haematological ...

    African Journals Online (AJOL)

    The high prevalence rate of diabetes mellitus (DM) in the developing world and its attendant high cost on healthcare have necessitated search for cheaper, effective and readily available alternative therapies in plants. One of such plants used in Nigeria is Newbouldia laevis (P. Beauv) (NLE). Its effect on erythrocyte fragility, ...

  14. Erythrocyte potassium and glutathione polymorphism determination ...

    African Journals Online (AJOL)

    This research is aimed at determining the erythrocyte potassium and glutathione polymorphisms and also to identify the relationship among the various blood parameters in Saanen x Malta crossbred goat raised in Turkey. The allele gene frequencies of KH and KL associated with the potassium concentration were ...

  15. Facilitated Uptake of a Bioactive Metabolite of Maritime Pine Bark Extract (Pycnogenol) into Human Erythrocytes

    Science.gov (United States)

    Kurlbaum, Max; Mülek, Melanie; Högger, Petra

    2013-01-01

    Many plant secondary metabolites exhibit some degree of biological activity in humans. It is a common observation that individual plant-derived compounds in vivo are present in the nanomolar concentration range at which they usually fail to display measurable activity in vitro. While it is debatable that compounds detected in plasma are not the key effectors of bioactivity, an alternative hypothesis may take into consideration that measurable concentrations also reside in compartments other than plasma. We analysed the binding of constituents and the metabolite δ-(3,4-dihydroxy-phenyl)-γ-valerolactone (M1), that had been previously detected in plasma samples of human consumers of pine bark extract Pycnogenol, to human erythrocytes. We found that caffeic acid, taxifolin, and ferulic acid passively bind to red blood cells, but only the bioactive metabolite M1 revealed pronounced accumulation. The partitioning of M1 into erythrocytes was significantly diminished at higher concentrations of M1 and in the presence of glucose, suggesting a facilitated transport of M1 via GLUT-1 transporter. This concept was further supported by structural similarities between the natural substrate α-D-glucose and the S-isomer of M1. After cellular uptake, M1 underwent further metabolism by conjugation with glutathione. We present strong indication for a transporter-mediated accumulation of a flavonoid metabolite in human erythrocytes and subsequent formation of a novel glutathione adduct. The physiologic role of the adduct remains to be elucidated. PMID:23646194

  16. Facilitated uptake of a bioactive metabolite of maritime pine bark extract (pycnogenol into human erythrocytes.

    Directory of Open Access Journals (Sweden)

    Max Kurlbaum

    Full Text Available Many plant secondary metabolites exhibit some degree of biological activity in humans. It is a common observation that individual plant-derived compounds in vivo are present in the nanomolar concentration range at which they usually fail to display measurable activity in vitro. While it is debatable that compounds detected in plasma are not the key effectors of bioactivity, an alternative hypothesis may take into consideration that measurable concentrations also reside in compartments other than plasma. We analysed the binding of constituents and the metabolite δ-(3,4-dihydroxy-phenyl-γ-valerolactone (M1, that had been previously detected in plasma samples of human consumers of pine bark extract Pycnogenol, to human erythrocytes. We found that caffeic acid, taxifolin, and ferulic acid passively bind to red blood cells, but only the bioactive metabolite M1 revealed pronounced accumulation. The partitioning of M1 into erythrocytes was significantly diminished at higher concentrations of M1 and in the presence of glucose, suggesting a facilitated transport of M1 via GLUT-1 transporter. This concept was further supported by structural similarities between the natural substrate α-D-glucose and the S-isomer of M1. After cellular uptake, M1 underwent further metabolism by conjugation with glutathione. We present strong indication for a transporter-mediated accumulation of a flavonoid metabolite in human erythrocytes and subsequent formation of a novel glutathione adduct. The physiologic role of the adduct remains to be elucidated.

  17. Uric acid increases erythrocyte aggregation: Implications for cardiovascular disease.

    Science.gov (United States)

    Sloop, Gregory D; Bialczak, Jessica K; Weidman, Joseph J; St Cyr, J A

    2016-10-05

    Uric acid may be a risk factor for atherosclerotic cardiovascular disease, although the data conflict and the mechanism by which it may cause cardiovascular disease is uncertain. This study was performed to test the hypothesis that uric acid, an anion at physiologic pH, can cause erythrocyte aggregation, which itself is associated with cardiovascular disease. Normal erythrocytes and erythrocytes with a positive direct antiglobulin test for surface IgG were incubated for 15 minutes in 14.8 mg/dL uric acid. Erythrocytes without added uric acid were used as controls. Erythrocytes were then examined microscopically for aggregation. Aggregates of up to 30 erythrocytes were noted when normal erythrocytes were incubated in uric acid. Larger aggregates were noted when erythrocytes with surface IgG were incubated in uric acid. Aggregation was negligible in controls. These data show that uric acid causes erythrocyte aggregation. The most likely mechanism is decreased erythrocyte zeta potential. Erythrocyte aggregates will increase blood viscosity at low shear rates and increase the risk of atherothrombosis. In this manner, hyperuricemia and decreased zeta potential may be risk factors for atherosclerotic cardiovascular disease.

  18. Decreased Erythrocyte CCS Content is a Biomarker of Copper Overload in Rats

    Directory of Open Access Journals (Sweden)

    Jesse Bertinato

    2010-07-01

    Full Text Available Copper (Cuis an essential trace metal that is toxic in excess. It is therefore important to be able to accurately assess Cu deficiency or overload. Cu chaperone for Cu/Zn superoxide dismutase (CCS protein expression is elevated in tissues of Cu-deficient animals. Increased CCS content in erythrocytes is particularly sensitive to decreased Cu status. Given the lack of a non-invasive, sensitive and specific biomarker for the assessment of Cu excess, we investigated whether CCS expression in erythrocytes reflects Cu overload. Rats were fed diets containing normal or high levels of Cu for 13 weeks. Diets contained 6.3 ± 0.6 (Cu-N, 985 ± 14 (Cu-1000 or 1944 ± 19 (Cu-2000 mg Cu/kg diet. Rats showed a variable response to the high Cu diets. Some rats showed severe Cu toxicity, while other rats showed no visible signs of toxicity and grew normally. Also, some rats had high levels of Cu in liver, whereas others had liver Cu concentrations within the normal range. Erythrocyte CCS protein expression was 30% lower in Cu-2000 rats compared to Cu-N rats (P < 0.05. Notably, only rats that accumulated high levels of Cu in liver had lower erythrocyte CCS (47% reduction, P < 0.05 compared to rats fed normal levels of Cu. Together, these data indicate that decreased erythrocyte CCS content is associated with Cu overload in rats and should be evaluated further as a potential biomarker for assessing Cu excess in humans.

  19. Conjugated Bilirubin Triggers Anemia by Inducing Erythrocyte Death

    Science.gov (United States)

    Lang, Elisabeth; Gatidis, Sergios; Freise, Noemi F; Bock, Hans; Kubitz, Ralf; Lauermann, Christian; Orth, Hans Martin; Klindt, Caroline; Schuier, Maximilian; Keitel, Verena; Reich, Maria; Liu, Guilai; Schmidt, Sebastian; Xu, Haifeng C; Qadri, Syed M; Herebian, Diran; Pandyra, Aleksandra A; Mayatepek, Ertan; Gulbins, Erich; Lang, Florian; Häussinger, Dieter; Lang, Karl S; Föller, Michael; Lang, Philipp A

    2015-01-01

    Hepatic failure is commonly associated with anemia, which may result from gastrointestinal bleeding, vitamin deficiency, or liver-damaging diseases, such as infection and alcohol intoxication. At least in theory, anemia during hepatic failure may result from accelerated clearance of circulating erythrocytes. Here we show that bile duct ligation (BDL) in mice leads to severe anemia despite increased reticulocyte numbers. Bilirubin stimulated suicidal death of human erythrocytes. Mechanistically, bilirubin triggered rapid Ca2+ influx, sphingomyelinase activation, formation of ceramide, and subsequent translocation of phosphatidylserine to the erythrocyte surface. Consistent with our in vitro and in vivo findings, incubation of erythrocytes in serum from patients with liver disease induced suicidal death of erythrocytes in relation to their plasma bilirubin concentration. Consistently, patients with hyperbilirubinemia had significantly lower erythrocyte and significantly higher reticulocyte counts compared to patients with low bilirubin levels. Conclusion: Bilirubin triggers suicidal erythrocyte death, thus contributing to anemia during liver disease. (Hepatology 2015;61:275–284) PMID:25065608

  20. Study of erythrocyte membrane fluctuation using light scattering analysis

    Science.gov (United States)

    Lee, Hoyoon; Lee, Sangyun; Park, YongKeun; Shin, Sehyun

    2016-03-01

    It is commonly known that alteration of erythrocyte deformability lead to serious microcirculatory diseases such as retinopathy, nephropathy, etc. Various methods and technologies have been developed to diagnose such membrane properties of erythrocytes. In this study, we developed an innovative method to measure hemorheological characteristics of the erythrocyte membrane using a light scattering analysis with simplified optic setting and multi-cell analysis as well. Light scattering intensity through multiple erythrocytes and its power density spectrum were obtained. The results of light scattering analyses were compared in healthy control and artificially hardened sample which was treated with glutaraldehyde. These results were further compared with conventional assays to measure deformable property in hemorheology. We found that light scattering information would reflect the disturbance of membrane fluctuation in artificially damaged erythrocytes. Therefore, measuring fluctuation of erythrocyte membrane using light scattering signal could facilitate simple and precise diagnose of pathological state on erythrocyte as well as related complications.

  1. Erythrocyte-based Pig-a gene mutation assay: demonstration of cross-species potential.

    Science.gov (United States)

    Phonethepswath, Souk; Bryce, Steven M; Bemis, Jeffrey C; Dertinger, Stephen D

    2008-12-08

    Glycosylphosphatidylinositol (GPI) anchors attach specific proteins to the cell surface of hematopoietic cells. Of the genes required to form GPI anchors, only Pig-a is located on the X-chromosome. Prior work with rats suggests that the GPI anchor deficient phenotype is a reliable indicator of Pig-a mutation [Bryce et al., Environ. Mol. Mutagen., 49 (2008) 256-264]. The current report extends this line of investigation by describing simplified blood handling procedures, and by testing the assay principle in a second species, Mus musculus. With this method, erythrocytes are isolated, incubated with anti-CD24-PE, and stained with SYTO 13. Flow cytometric analyses quantify GPI anchor-deficient erythrocytes and reticulocytes. After reconstruction experiments with mutant-mimicking cells demonstrated that the analytical performance of the method is high, CD-1 mice were treated on three occasions with 7,12-dimethyl-1,2-benz[a]anthracene (DMBA, 75 mg/kg/day) or ethyl-N-nitrosourea (ENU, 40 mg/kg/day). Two weeks after the final treatment, DMBA-treated mice were found to exhibit markedly elevated frequencies of GPI anchor deficient erythrocytes and reticulocytes. For the ENU experiment, blood specimens were collected at weekly intervals over a 5-week period. Whereas the frequencies of mutant reticulocytes were significantly elevated 1 week after the last administration, the erythrocyte population was unchanged until the second week. Thereafter, both populations exhibited persistently elevated frequencies for the duration of the experiment (mean frequency at termination=310x10(-6) and 523x10(-6) for erythrocyte and reticulocyte populations, respectively). These data provide evidence that Pig-a mutation does not convey an appreciable positive or negative cell survival advantage to affected erythroid progenitors, although they do suggest that affected erythrocytes have a reduced lifespan in circulation. Collectively, accumulated data support the hypothesis that flow cytometric

  2. Flow cytometric assessment of canine erythrocytes and platelets for dog erythrocyte antigen 1.1.

    Science.gov (United States)

    Lucidi, Cynthia de A; Takahira, Regina K; Gerlach, John A; Davis, John M; Schwartz, Kenneth A; Scott, Michael A

    2011-12-01

    In human medicine, transfusion of ABO-mismatched platelets has been associated with shortened platelet survival and refractoriness to platelet transfusion because of expression of certain blood group antigens on platelets. It remains unknown if canine platelets express dog erythrocyte antigens (DEAs). The aim of this study was to develop a flow cytometric assay for DEA 1.1 and determine whether DEA 1.1 is present on canine platelets. Blood was collected from 172 clinically healthy dogs. Platelets and erythrocytes from each dog were tested for DEA 1.1 by flow cytometry using anti-DEA 1.1 blood-typing sera. Erythrocytes from each dog were also assessed for DEA 1.1 using a standard tube-typing test (T1) and using a second tube method (T2), if the flow cytometric and T1 results differed. Using flow cytometry, DEA 1.1 was detected on erythrocytes of all 110 dogs shown by T1 or T2 testing to be DEA 1.1-positive. Initial results of the T1 test had a diagnostic accuracy of 93% (160 correct/172 tests). The frequency of erythrocyte DEA 1.1 positivity in previously untyped dogs (n = 118) was 56%. DEA 1.1 expression was not detected on platelets from DEA 1.1-positive dogs. Flow cytometry was a reliable method for detection of DEA 1.1 on canine erythrocytes. The absence of DEA 1.1 on platelets from DEA 1.1-positive dogs suggests that their platelets do not express DEA 1.1 and will not induce production of anti-DEA 1.1 antibodies that might lead to platelet refractoriness or reactions to a subsequent transfusion of DEA 1.1-positive erythrocytes. © 2011 American Society for Veterinary Clinical Pathology.

  3. HEMOLYSIS OF RABBIT ERYTHROCYTES BY PURIFIED STAPHYLOCOCCAL ALPHA-TOXIN II.

    Science.gov (United States)

    Cooper, Louis Z.; Madoff, Morton A.; Weinstein, Louis

    1964-01-01

    Cooper, Louis Z. (New England Center Hospital, Boston, Mass.), Morton A. Madoff, and Louis Weinstein. Hemolysis of rabbit erythrocytes by purified staphylococcal alpha-toxin. II. Effect of inhibitors on the hemolytic sequence. J. Bacteriol. 87:136–144. 1964.—Study of the time course of hemolysis of rabbit erythrocytes by purified staphylococcal alpha-lysin revealed that the specific toxin-red cell reaction occurs during the prelytic period. This reaction could be prevented or decreased by alpha-lysin antitoxin added early, but not by antitoxin added at the end of the prelytic phase or at any time thereafter. In contrast, hemolysis is suppressed temporarily by sucrose and permanently by polyethylene glycol, even when these are added during the period of rapid release of hemoglobin. When sucrose is present together with alpha-lysin and red cells only during the prelytic period, and when the cells are then washed and resuspended in phosphate-buffered saline, their subsequent hemolysis is not altered by the presence of the sugar. This is not so when antitoxin is employed. When erythrocytes are laked by a measured excess of alpha-lysin, only a portion of the original hemolytic activity can be recovered. Repeated exposure of lysin to red cells produces a loss of activity represented by a linear function when logs of residual activity are plotted sequentially. Once alpha-lysin has reacted with red cells, it does not appear to be available for attachment to other erythrocytes. PMID:14102846

  4. Functional and structural changes of human erythrocyte catalase induced by cimetidine: proposed model of binding.

    Science.gov (United States)

    Yazdi, Fatemeh; Minai-Tehrani, Dariush; Jahngirvand, Mahboubeh; Almasirad, Ali; Mousavi, Zahra; Masoud, Masoudeh; Mollasalehi, Hamidreza

    2015-06-01

    In erythrocyte, catalase plays an important role to protect cells from hydrogen peroxide toxicity. Hydrogen peroxide is a byproduct compound which is produced during metabolic pathway of cells. Cimetidine, a histamine H2 receptor antagonist, is used for gastrointestinal tract diseases and prevents the extra release of gastric acid. In this study, the effect of cimetidine on the activity of human erythrocyte catalase was investigated. Erythrocytes were broken by hypotonic solution. The supernatant was used for catalase assay and kinetics study. Lineweaver-Burk plot was performed to determine the type of inhibition. The kinetics data revealed that cimetidine inhibited the catalase activity by mixed inhibition. The IC50 (1.54 μM) and Ki (0.45 μM) values of cimetidine determined that the drug was bound to the enzyme with high affinity. Circular dichroism and fluorescence measurement showed that the binding of cimetidine to the enzyme affected the content of secondary structure of the enzyme as well as its conformational changes. Docking studies were carried out to detect the site in which the drug was bound to the enzyme. Molecular modeling and energy calculation of the binding showed that the cyanoguanidine group of the drug connected to Asp59 via two hydrogen bonds, while the imidazole group of the drug interacted with Phe64 in the enzyme by a hydrophobic interaction. In conclusion, cimetidine could bind to human erythrocyte catalase, and its interaction caused functional and conformational changes in the enzyme.

  5. Effect of Progesterone and Synthetic Progestins on Whole Blood Clot Formation and Erythrocyte Structure.

    Science.gov (United States)

    Swanepoel, Albe C; Emmerson, Odette; Pretorius, Etheresia

    2017-06-01

    Combined oral contraceptive (COC) use is a risk factor for venous thrombosis (VT) and related to the specific type of progestin used. VT is accompanied by inflammation and pathophysiological clot formation, that includes aberrant erythrocytes and fibrin(ogen) interactions. In this paper, we aim to determine the influence of progesterone and different synthetic progestins found in COCs on the viscoelasticity of whole blood clots, as well as erythrocyte morphology and membrane ultrastructure, in an in vitro laboratory study. Thromboelastography (TEG), light microscopy, and scanning electron microscopy were our chosen methods. Our results point out that progestins influence the rate of whole blood clot formation. Alterations to erythrocyte morphology and membrane ultrastructure suggest the presence of eryptosis. We also note increased rouleaux formation, erythrocyte aggregation, and spontaneous fibrin formation in whole blood which may explain the increased risk of VT associated with COC use. Although not all COC users will experience a thrombotic event, individuals with a thrombotic predisposition, due to inflammatory or hematological illness, should be closely monitored to prevent pathological thrombosis.

  6. Plasmodium falciparum avoids change in erythrocytic surface expression of phagocytosis markers during inhibition of nitric oxide synthase activity.

    Science.gov (United States)

    Hempel, Casper; Kohnke, Hannes; Maretty, Lasse; Jensen, Peter Ø; Staalsø, Trine; Kurtzhals, Jørgen A L

    2014-11-01

    Nitric oxide (NO) accumulates in Plasmodium falciparum-infected erythrocytes. It may be produced by a parasite NO synthase (NOS) or by nitrate reduction. The parasite's benefit of NO accumulation is not understood. We investigated if inhibiting the P. falciparum NOS with specific and unspecific NOS inhibitors led to a decrease in intraerythrocytic NO accumulation and if this was associated with a change in surface expression of the phagocytosis markers CD47 and phosphatidyl serine. The specific inducible NOS inhibitors l-canavanine and GW274150 dose-dependently decreased intraerythrocytic NO while l-NMMA (an unspecific NOS inhibitor) and caveolin-1 scaffolding domain peptide (a specific endothelial NOS inhibitor) did not affect NO levels. Phosphatidyl serine externalization markedly increased upon P. falciparum infection. l-canavanine did not modify this whereas caveolin-1 scaffolding domain peptide increased the fraction of phosphatidyl serine exposing cells significantly. The infection did not change the level of expression of neither total CD47 nor its oxidized form. Unrelated to NOS inhibition, incubation with caveolin-1 scaffolding domain peptide lead to a decrease in oxidized CD47. In conclusion, the data imply that NOS inhibitors decrease NO accumulation in P. falciparum-infected erythrocytes but this does not correlate with the level of two major erythrocytic phagocytosis markers. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Male circumcision to prevent syphilis in 1855 and HIV in 1986 is supported by the accumulated scientific evidence to 2015: Response to Darby.

    Science.gov (United States)

    Morris, Brian J; Wamai, Richard G; Krieger, John N; Banerjee, Joya; Klausner, Jeffrey D

    2017-10-01

    An article by Darby disparaging male circumcision (MC) for syphilis prevention in Victorian times (1837-1901) and voluntary medical MC programs for HIV prevention in recent times ignores contemporary scientific evidence. It is one-sided and cites outlier studies as well as claims by MC opponents that support the author's thesis, but ignores high quality randomised controlled trials and meta-analyses. While we agree with Darby that risky behaviours contribute to syphilis and HIV epidemics, there is now compelling evidence that MC helps reduce both syphilis and HIV infections. Although some motivations for MC in Victorian times were misguided, others, such as protection against syphilis, penile cancer, phimosis, balanitis and poor hygiene have stood the test of time. In the absence of a cure or effective prophylactic vaccine for HIV, MC should help lower heterosexually acquired HIV, especially when coupled with other interventions such as condoms and behaviour. This should save lives, as well as reducing costs and suffering. In contrast to Darby, our evaluation of the evidence leads us to conclude that MC would likely have helped reduce syphilis in Victorian times and, in the current era, will help lower both syphilis and HIV, so improving global public health.

  8. Inhibition of Suicidal Erythrocyte Death by Reversine

    Directory of Open Access Journals (Sweden)

    Mohamed Jemaà

    2017-04-01

    Full Text Available Background/Aims: The A3 adenosine receptor antagonist reversine (2-(4-morpholinoanilino-6-cyclohexylaminopurine influences cellular differentiation, inhibits cell proliferation, induces cell-cycle arrest, triggers apoptosis, causes cell swelling with polyploidy and stimulates autophagy. The effect on apoptosis involves mitochondria and caspases. Erythrocytes are lacking mitochondria but express caspases and are, similar to apoptosis of nucleated cells, able to enter suicidal erythrocyte death or eryptosis. Stimulators of eryptosis include increase of cytosolic Ca2+ activity ([Ca2+]i, energy depletion and oxidative stress. The present study explored, whether reversine influences eryptosis. Methods: Flow cytometry was employed to quantify phosphatidylserine exposure at the cell surface from annexin-V-binding and cell volume from forward scatter. Measurements were made without or with energy depletion (glucose deprivation for 48 hours, Ca2+ loading (30 minutes treatment with 1 µM Ca2+ ionophore ionomycin, or oxidative stress (15 min exposure to 0.3 mM tert-butylhydroperoxide. Results: A 48 hours exposure of human erythrocytes to reversine (1-10 µM did not significantly modify the percentage of annexin-V-binding cells and forward scatter. Energy depletion, Ca2+ loading, and oxidative stress were each followed by profound and significant increase of the percentage annexin-V-binding erythrocytes and a significant decrease of forward scatter. The effects of each, Ca2+ loading, energy depletion and oxidative stress on annexin-V-binding were significantly blunted in the presence of reversine (1-10 µM. The effect of ionomycin, but not the effects of energy depletion and oxidative stress on forward scatter were again significantly blunted in the presence of reversine (≥1 µM]. Conclusions: Reversine is a powerful inhibitor of cell membrane scrambling following energy depletion, Ca2+ loading and oxidative stress.

  9. Lapatinib Induced Suicidal Death of Human Erythrocytes

    Directory of Open Access Journals (Sweden)

    Jens Zierle

    2015-12-01

    Full Text Available Background/Aims: The human epidermal growth factor receptors tyrosine kinase inhibitor lapatinib has been shown to trigger suicidal death or apoptosis of tumor cells and is thus used for the treatment of malignancy. Side effects of lapatinib include anemia, which could, at least in theory, result from stimulation of eryptosis, the suicidal death of erythrocytes which is characterized by cell shrinkage and phospholipid scrambling of the cell membrane leading to phosphatidylserine translocation to the erythrocyte surface. Mechanisms involved in the triggering of eryptosis include oxidative stress, increase of cytosolic Ca2+ activity ([Ca2+]i, and ceramide. The present study explored, whether lapatinib induces eryptosis. Methods: Phosphatidylserine exposure at the cell surface was estimated from annexin-V-binding, cell volume from forward scatter, [Ca2+]i from Fluo3-fluorescence, abundance of reactive oxygen species (ROS from DCFDA dependent fluorescence, and ceramide abundance utilizing labelled specific antibodies. Results: A 48 hours exposure of human erythrocytes to lapatinib (≥ 1 µg/ml significantly increased the percentage of annexin-V-binding cells, and significantly decreased forward scatter. Lapatinib (7.5 µg/ml did not significantly modify DCFDA fluorescence and ceramide abundance. Lapatinib slightly, but significantly decreased Fluo3-fluorescence (≥ 5 µg/ml. Lapatinib (7.5 µg/ml enhanced the annexin-V-binding in the presence of the Ca2+ ionophore ionomycin (1 µM without significantly modifying Fluo3 fluorescence in the presence of ionomycin. The effect of lapatinib on forward scatter but not on annexin-V-binding was significantly blunted by removal of extracellular Ca2+. Conclusion: Lapatinib triggers cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect occurring despite decrease of cytosolic Ca2+ activity.

  10. Induction of Suicidal Erythrocyte Death by Novobiocin

    Directory of Open Access Journals (Sweden)

    Adrian Lupescu

    2014-03-01

    Full Text Available Background: Novobiocin, an aminocoumarin antibiotic, interferes with heat shock protein 90 and hypoxia inducible factor dependent gene expression and thus compromises cell survival. Similar to survival of nucleated cells, erythrocyte survival could be disrupted by eryptosis, the suicidal erythrocyte death characterized by cell shrinkage and by phospholipd scrambling of the cell membrane with phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include increase of cytosolic Ca2+-activity ([Ca2+]i. The Ca2+ sensitivity of phospholipid scrambling is enhanced by ceramide. The present study explored, whether novobiocin elicits eryptosis. Methods: [Ca2+]i was estimated from Fluo3-fluorescence, ceramide abundance utilizing fluorescent antibodies, cell volume from forward scatter, phosphatidylserine-exposure from annexin V binding. Results: A 48 hours exposure to novobiocin (500 µM was followed by a significant increase of [Ca2+]i, decrease of forward scatter, increase of annexin-V-binding and enhanced ceramide formation. Removal of extracellular Ca2+ virtually abrogated the increase of annexin-V-binding following novobiocin exposure. Conclusions: Novobiocin stimulates eryptosis, an effect at least in part due to entry of extracellular Ca2+ and formation of ceramide.

  11. An Increased Dietary Supply of Medium-Chain Fatty Acids during Early Weaning in Rodents Prevents Excessive Fat Accumulation in Adulthood

    Directory of Open Access Journals (Sweden)

    Bert J. M. van de Heijning

    2017-06-01

    Full Text Available Medium-chain fatty acids (MCFA are a directly and readily absorbed source of energy. Exposure early-in-life to increased MCFA levels might affect development and impact (lipid metabolism later in life. We tested whether an increased MCFA intake early-in-life positively affects adult body composition and metabolic status when challenged by a western-style diet (WSD. Male offspring of C57Bl/6j mice and Wistar rats were fed a control diet (CTRL; 10 w% fat, 14% MCFA or a medium-chain triglycerides (MCT diet with 20% MCFA until postnatal (PN day 42, whereupon animals were fed a WSD (10 w% fat until PN day 98. Body composition was monitored by Dual Energy X-ray Absorptiometry (DEXA. In rats, glucose homeostasis was assessed by glucose tolerance test (GTT and insulin tolerance test (ITT; in mice, the HOmeostasis Model Assessment of Insulin Resistance (HOMA-IR was calculated. At autopsy on PN day 98, plasma lipid profiles, glucose, insulin, and adipokines were measured; organs and fat pads were collected and the adipocyte size distribution was analysed. Milk analysis in mice showed that the maternal MCT diet was not translated into milk, and pups were thus only exposed to high MCT levels from early weaning onward: PN day 16 until 42. Mice exposed to MCT showed 28% less fat accumulation vs. CTRL during WSD. The average adipocyte cell size, fasting plasma triglycerides (TG, and leptin levels were reduced in MCT mice. In rats, no effects were found on the adult body composition, but the adipocyte cell size distribution shifted towards smaller adipocytes. Particularly mice showed positive effects on glucose homeostasis and insulin sensitivity. Increased MCFA intake early-in-life protected against the detrimental effects of an obesogenic diet in adulthood.

  12. Milk fat globule membrane coating of large lipid droplets in the diet of young mice prevents body fat accumulation in adulthood.

    Science.gov (United States)

    Baars, Annemarie; Oosting, Annemarie; Engels, Eefje; Kegler, Diane; Kodde, Andrea; Schipper, Lidewij; Verkade, Henkjan J; van der Beek, Eline M

    2016-06-01

    Epidemiological studies have demonstrated protective effects of breast-feeding on childhood obesity. Differences between human milk and infant milk formula (IMF) in dietary lipid structure may contribute to this effect. In our mouse model, feeding a diet containing large lipid droplets coated with phospholipids (PL) (Nuturis®; PL of milk fat globule membrane (MFGM) fraction origin) in early life protected against excessive body fat accumulation following a diet challenge in adult life. We now set out to determine the relevance of increased droplet size and/or MFGM lipid droplet coating to the observed anti-obesogenic effects in adult life. From day 16 to 42, male mouse pups were exposed to diets with small (S) or large (L) lipid droplets (0·3 v. 2·9 µm average mode diameter, respectively), either without MFGM or with MFGM coating around the lipid droplet, resulting in four groups: S (control diet), L, Scoating and Lcoating (Nuturis® IMF diet). Mice were subsequently challenged with a Western-style diet until dissection at postnatal day 98. A non-challenged group served as reference (REF). We repeatedly determined body composition between postnatal day 42 and 98. At day 98 plasma and gene expression measurements were performed. Only the Nuturis® IMF diet (Lcoating) in early life containing MFGM-coated large lipid droplets reduced body fat mass to a level comparable with the REF group. These data support the notion that the structural aspects of lipids in human milk, for example, both lipid droplet size as well as the MFGM coating, may contribute to its reported protective effect against obesity in later life.

  13. Differential time‐dependent volumetric and surface area changes and delayed induction of new permeation pathways in P. falciparum‐infected hemoglobinopathic erythrocytes

    Science.gov (United States)

    Waldecker, Mailin; Dasanna, Anil K.; Lansche, Christine; Linke, Marco; Srismith, Sirikamol; Cyrklaff, Marek; Sanchez, Cecilia P.; Schwarz, Ulrich S.

    2016-01-01

    Abstract During intraerythrocytic development, Plasmodium falciparum increases the ion permeability of the erythrocyte plasma membrane to an extent that jeopardizes the osmotic stability of the host cell. A previously formulated numeric model has suggested that the parasite prevents premature rupture of the host cell by consuming hemoglobin (Hb) in excess of its own anabolic needs. Here, we have tested the colloid‐osmotic model on the grounds of time‐resolved experimental measurements on cell surface area and volume. We have further verified whether the colloid‐osmotic model can predict time‐dependent volumetric changes when parasites are grown in erythrocytes containing the hemoglobin variants S or C. A good agreement between model‐predicted and empirical data on both infected erythrocyte and intracellular parasite volume was found for parasitized HbAA and HbAC erythrocytes. However, a delayed induction of the new permeation pathways needed to be taken into consideration for the latter case. For parasitized HbAS erythrocyte, volumes diverged from model predictions, and infected erythrocytes showed excessive vesiculation during the replication cycle. We conclude that the colloid‐osmotic model provides a plausible and experimentally supported explanation of the volume expansion and osmotic stability of P. falciparum‐infected erythrocytes. The contribution of vesiculation to the malaria‐protective function of hemoglobin S is discussed. PMID:27450804

  14. Hydrochlorothiazide, but not Candesartan, aggravates insulin resistance and causes visceral and hepatic fat accumulation: the mechanisms for the diabetes preventing effect of Candesartan (MEDICA) Study

    DEFF Research Database (Denmark)

    Eriksson, J.W.; Jansson, P.A.; Carlberg, B.

    2008-01-01

    Treatment with angiotensin II receptor blockers is associated with lower risk for the development of type 2 diabetes mellitus compared with thiazide diuretics. The Mechanisms for the Diabetes Preventing Effect of Candesartan Study addressed insulin action and secretion and body fat distribution...... after treatment with candesartan, hydrochlorothiazide, and placebo. Twenty-six nondiabetic, abdominally obese, hypertensive patients were included in a multicenter 3-way crossover trial, and 22 completers (by predefined criteria; 10 men and 12 women) were included in the analyses. They underwent 12-week...... treatment periods with candesartan (C; 16 to 32 mg), hydrochlorothiazide (H; 25 to 50 mg), and placebo (P), respectively, and the treatment order was randomly assigned and double blinded. Intravenous glucose tolerance tests and euglycemic hyperinsulinemic (56 mU/m(2) per minute) clamps were performed...

  15. Metabolomic analysis of normal and sickle cell erythrocytes.

    Science.gov (United States)

    Darghouth, D; Koehl, B; Junot, C; Roméo, P-H

    2010-09-01

    Metabolic signatures of specialized circulating hematopoietic cells in physiological or human hematological diseases start to be described. We use a simple and highly reproductive extraction method of erythrocytes metabolites coupled with a liquid chromatography-mass spectrometry based metabolites profiling method to determine metabolomes of normal and sickle cell erythrocytes. Sickle cell erythrocytes and normal erythrocytes metabolomes display major differences in glycolysis, in glutathione, in ascorbate metabolisms and in metabolites associated to membranes turnover. In addition, the amounts of metabolites derived from urea cycle and NO metabolism that partly take place within erythrocyte were different between normal and sickle cell erythrocytes. These results show that metabolic profiling of red blood cell diseases can now be determined and might indicate new biomarkers that can be used for the follow-up of sickle cell patients. Copyright 2010. Published by Elsevier SAS.

  16. Moringa Leaves Prevent Hepatic Lipid Accumulation and Inflammation in Guinea Pigs by Reducing the Expression of Genes Involved in Lipid Metabolism

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    Manal Mused Almatrafi

    2017-06-01

    Full Text Available To investigate the mechanisms by which Moringa oleifera leaves (ML modulate hepatic lipids, guinea pigs were allocated to either control (0% ML, 10% Low Moringa (LM or 15% High Moringa (HM diets with 0.25% dietary cholesterol to induce hepatic steatosis. After 6 weeks, guinea pigs were sacrificed and liver and plasma were collected to determine plasma lipids, hepatic lipids, cytokines and the expression of genes involved in hepatic cholesterol (CH and triglyceride (TG metabolism. There were no differences in plasma lipids among groups. A dose-response effect of ML was observed in hepatic lipids (CH and TG with the lowest concentrations in the HM group (p < 0.001, consistent with histological evaluation of lipid droplets. Hepatic gene expression of diglyceride acyltransferase-2 and peroxisome proliferator activated receptor-γ, as well as protein concentrations interleukin (IL-1β and interferon-γ, were lowest in the HM group (p < 0.005. Hepatic gene expression of cluster of differentiation-68 and sterol regulatory element binding protein-1c were 60% lower in both the LM and HM groups compared to controls (p < 0.01. This study demonstrates that ML may prevent hepatic steatosis by affecting gene expression related to hepatic lipids synthesis resulting in lower concentrations of cholesterol and triglycerides and reduced inflammation in the liver.

  17. Moringa Leaves Prevent Hepatic Lipid Accumulation and Inflammation in Guinea Pigs by Reducing the Expression of Genes Involved in Lipid Metabolism

    Science.gov (United States)

    Almatrafi, Manal Mused; Vergara-Jimenez, Marcela; Murillo, Ana Gabriela; Norris, Gregory H.; Blesso, Christopher N.; Fernandez, Maria Luz

    2017-01-01

    To investigate the mechanisms by which Moringa oleifera leaves (ML) modulate hepatic lipids, guinea pigs were allocated to either control (0% ML), 10% Low Moringa (LM) or 15% High Moringa (HM) diets with 0.25% dietary cholesterol to induce hepatic steatosis. After 6 weeks, guinea pigs were sacrificed and liver and plasma were collected to determine plasma lipids, hepatic lipids, cytokines and the expression of genes involved in hepatic cholesterol (CH) and triglyceride (TG) metabolism. There were no differences in plasma lipids among groups. A dose-response effect of ML was observed in hepatic lipids (CH and TG) with the lowest concentrations in the HM group (p < 0.001), consistent with histological evaluation of lipid droplets. Hepatic gene expression of diglyceride acyltransferase-2 and peroxisome proliferator activated receptor-γ, as well as protein concentrations interleukin (IL)-1β and interferon-γ, were lowest in the HM group (p < 0.005). Hepatic gene expression of cluster of differentiation-68 and sterol regulatory element binding protein-1c were 60% lower in both the LM and HM groups compared to controls (p < 0.01). This study demonstrates that ML may prevent hepatic steatosis by affecting gene expression related to hepatic lipids synthesis resulting in lower concentrations of cholesterol and triglycerides and reduced inflammation in the liver. PMID:28640194

  18. Acquisition and decay of antibodies to pregnancy-associated variant antigens on the surface of Plasmodium falciparum-infected erythrocytes that protect against placental parasitemia

    DEFF Research Database (Denmark)

    Staalsoe, T; Megnekou, R; Fievét, N

    2001-01-01

    Otherwise clinically immune women in areas endemic for malaria are highly susceptible to Plasmodium falciparum malaria during their first pregnancy. Pregnancy-associated malaria (PAM) is characterized by placental accumulation of infected erythrocytes that adhere to chondroitin sulfate A (CSA). S...

  19. Hepatic or splenic targeting of carrier erythrocytes: a murine model

    Energy Technology Data Exchange (ETDEWEB)

    Zocchi, E.; Guida, L.; Benatti, U.; Canepa, M.; Borgiani, L.; Zanin, T.; De Flora, A.

    1987-10-01

    Carrier mouse erythrocytes, i.e., red cells, subjected to a dialysis technique involving transient hypotonic hemolysis and isotonic resealing were treated in vitro in three different ways: (a) energy depletion by exposure for 90 min at 42 degrees C; (b) desialylation by incubation with neuroaminidase; and (c) oxidative stress by incubation with H/sub 2/O/sub 2/ and NaN3. Procedure (c) afforded maximal damage, as shown by analysis of biochemical properties of the treated erythrocytes. Reinfusion in mice of the variously manipulated erythrocytes following their /sup 51/Cr labeling showed extensive fragilization as indicated by rapid clearance of radioactivity from the circulation. Moreover, both the energy-depleted and the neuraminidase-treated erythrocytes showed a preferential liver uptake, reaching 50 and 75%, respectively, within 2 h. On the other hand, exposure of erythrocytes to the oxidant stress triggered a largely splenic removal, accounting for almost 40% of the reinjected cells within 4 h. Transmission electron microscopy of liver from mice receiving energy-depleted erythrocytes demonstrated remarkable erythrocyte congestion within the sinusoids, followed by hyperactivity of Kupffer cells and by subsequent thickening of the perisinusoidal Disse space. Concomitantly, levels of serum transaminase activities were moderately increased. Each of the three procedures of manipulation of carrier erythrocytes may prove applicable under conditions where selective targeting of erythrocyte-encapsulated chemicals and drugs to either the liver or the spleen has to be achieved.

  20. [Functional state feature of erythrocytes in healthy term newborn infants].

    Science.gov (United States)

    Evsiukova, I I; Iakushenko, N S; Andreeva, A A; Shevel'kova, A A; Kolesova, T A; Katiukhin, L N; Dobrylko, I A; Mandukshev, I V

    2014-01-01

    Hematological parameters and functional status of erythrocytes were studied by the osmotic and ammonium loads in healthy newborns and in adults. Mean erythrocyte volume of newborns more than in adults. Significant difference index of osmotic fragility of neonates were observed in the transition from swelling to hemolysis. Kinetic of erythrocyte's hemolysis in the ammonium load was studied by low-angle light scattering (LaSca-analyzer). The percentage of erythrocyte hemolysis is lower and the velocity of hemolysis is 2.5 times slower in newborns than in adults.

  1. Evolution of erythrocyte morphology in amphibians (Amphibia: Anura

    Directory of Open Access Journals (Sweden)

    Jie Wei

    2015-10-01

    Full Text Available ABSTRACT We compared the morphology of the erythrocytes of five anurans, two toad species - Bufo gargarizans (Cantor, 1842 and Duttaphrynus melanostictus (Schneider, 1799 and three frog species - Fejervarya limnocharis (Gravenhorst, 1829, Microhyla ornata (Duméril & Bibron, 1841, and Rana zhenhaiensis (Ye, Fei & Matsui, 1995. We then reconstructed the ancestral state of erythrocyte size (ES and nuclear size (NS in amphibians based on a molecular tree. Nine morphological traits of erythrocytes were all significantly different among the five species. The results of principal component analysis showed that the first component (49.1% of variance explained had a high positive loading for erythrocyte length, nuclear length, NS and ratio of erythrocyte length/erythrocyte width; the second axis (28.5% of variance explained mainly represented erythrocyte width and ES. Phylogenetic generalized least squares analysis showed that the relationship between NS and ES was not affected by phylogenetic relationships although there was a significant linear relationship between these two variables. These results suggested that (1 the nine morphological traits of erythrocytes in the five anuran species were species-specific; (2 in amphibians, larger erythrocytes generally had larger nuclei.

  2. Variations on Fibrinogen-Erythrocyte Interactions during Cell Aging

    Science.gov (United States)

    Carvalho, Filomena A.; de Oliveira, Sofia; Freitas, Teresa; Gonçalves, Sónia; Santos, Nuno C.

    2011-01-01

    Erythrocyte hyperaggregation, a cardiovascular risk factor, is considered to be caused by an increase in plasma adhesion proteins, particularly fibrinogen. We have recently reported a specific binding between fibrinogen and an erythrocyte integrin receptor with a β3 or β3-like subunit. In this study we evaluate the influence of erythrocyte aging on the fibrinogen binding. By atomic force microscopy-based force spectroscopy measurements we found that increasing erythrocyte age, there is a decrease of the binding to fibrinogen by decreasing the frequency of its occurrence but not its force. This observation is reinforced by zeta-potential and fluorescence spectroscopy measurements. We conclude that upon erythrocyte aging the number of fibrinogen molecules bound to each cell decreases significantly, due to the progressive impairment of the specific fibrinogen-erythrocyte receptor interaction. Knowing that younger erythrocytes bind more to fibrinogen, we could presume that this population is the main contributor to the cardiovascular diseases associated with increased fibrinogen content in blood, which could disturb the blood flow. Our data also show that the sialic acids exposed on the erythrocyte membrane contribute for the interaction with fibrinogen, possibly by facilitating its binding to the erythrocyte membrane receptor. PMID:21464904

  3. Physicochemical Aspects of the Plasmodium chabaudi-Infected Erythrocyte

    Science.gov (United States)

    Hayakawa, Eri H.; Kobayashi, Seiki; Matsuoka, Hiroyuki

    2015-01-01

    Membrane electrochemical potential is a feature of the molecular profile of the cell membrane and the two-dimensional arrangement of its charge-bearing molecules. Plasmodium species, the causative agents of malaria, are intracellular parasites that remodel host erythrocytes by expressing their own proteins on erythrocyte membranes. Although various aspects of the modifications made to the host erythrocyte membrane have been extensively studied in some human Plasmodium species (such as Plasmodium falciparum), details of the structural and molecular biological modifications made to host erythrocytes by nonhuman Plasmodium parasites have not been studied. We employed zeta potential analysis of erythrocytes parasitized by P. chabaudi, a nonhuman Plasmodium parasite. From these measurements, we found that the surface potential shift was more negative for P. chabaudi-infected erythrocytes than for P. falciparum-infected erythrocytes. However, electron microscopic analysis of the surface of P. chabaudi-infected erythrocytes did not reveal any modifications as compared with nonparasitized erythrocytes. These results suggest that differences in the membrane modifications found herein represent unique attributes related to the pathogenesis profiles of the two different malaria parasite species in different host animals and that these features have been acquired through parasite adaptations acquired over long evolutionary time periods. PMID:26557685

  4. Monosaccharide transport in protein-depleted vesicles from erythrocyte membranes

    National Research Council Canada - National Science Library

    M A Zoccoli; G E Lienhard

    1977-01-01

    .... Based on comparisons between erythrocytes and vesicles with regard to specificity, temparture dependence, and effects of inhibitors, we conclude that sorbose uptake into the vesicles occurs by way...

  5. Aqueous extract of some indigenous medicinal plants inhibits glycation at multiple stages and protects erythrocytes from oxidative damage-an in vitro study.

    Science.gov (United States)

    Tupe, Rashmi S; Sankhe, Neena M; Shaikh, Shamim A; Phatak, Devyani V; Parikh, Juhi U; Khaire, Amrita A; Kemse, Nisha G

    2015-04-01

    Azadirachta indica, Emblica officinalis, Syzygium cumini and Terminalia bellirica are common in Indian system of traditional medicine for the prevention of diabetes and its complications. The aim of the present study was to comprehensively and comparatively investigate the antiglycation potential of these plant extracts at multiple stages and their possible protective effect against glycated albumin mediated toxicity to erythrocytes. Antiglycation activities of these plant extracts was measured by co-incubation of plant extract with bovine serum albumin-fructose glycation model. The multistage glycation markers- fructosamines (early stage), protein carbonyls (intermediate stage) and AGEs (late stage) are investigated along with measurement of thiols and β aggregation of albumin using amyloid-specific dyes-Congo red and Th T. Protection of erythrocytes from glycated albumin induced toxicity by these plant extracts was assessed by measuring erythrocytes hemolysis, lipid peroxidation, reduced glutathione and intracellular antioxidant capacity. Total phenolics, reducing power and antioxidant activities of the plant extracts were also measured. In vitro glycation assays showed that plant extracts exerted site specific inhibitory effects at multiple stages, with T. bellirica showing maximum attenuation. In erythrocytes, along with the retardation of glycated albumin induced hemolysis and lipid-peroxidation, T. bellirica considerably maintained cellular antioxidant potential. Significant positive correlations were observed between erythrocyte protection parameters with total phenolics. These plant extracts especially T. bellirica prevents glycation induced albumin modifications and subsequent toxicity to erythrocytes which might offer additional protection against diabetic vascular complications.

  6. Investigation of High-Speed Erythrocyte Flow and Erythrocyte-Wall Impact in a Lab-on-a-Chip.

    Science.gov (United States)

    Li, Ping; Zheng, Lu; Zhang, Di; Xie, Yonghui; Feng, Yi; Xie, Gongnan

    2016-11-01

    To better understand erythrocyte high-speed motion, collision characteristics, and collision-induced hemolysis probability in rotary blood pumps, a visual experimental investigation of high-speed erythrocyte flow and erythrocyte-wall collision in a lab-on-a-chip was performed. The erythrocyte suspension was driven by a microsyringe pump connected to the microchip, and the erythrocyte flow and erythrocyte-wall impact process were observed and imaged by an optical microscope and a high-speed camera. Two types of microchips with different impact surfaces (flat and curved) were employed. The motion and deformation features before and after collision were studied in detail. The results show that erythrocytes not only move along the flow direction in the flow plane but also rotate and roll in three-dimensional space. Erythrocytes keep discoid shape during the movement in the straight channel, but their deformations during collision are mainly classified into two types: erythrocyte structure is still stable and the erythrocyte performance can be ensured to a certain extent in the TypeA deformation, while the TypeB deformation makes the membrane more likely to fracture on the stretched side, increasing the probability of hemolysis. Furthermore, the movements and deformations of the erythrocytes after collision are analyzed and classified into two types: bouncing and slipping. Moreover, a simulation method for the flow in microchip was performed and validated through a comparison of the streamlines and experimental erythrocytes tracks, which can be further employed to predict the high-speed blood flow, associated with collision process in mechanical blood pump. Copyright © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  7. Storage-induced changes in erythrocyte membrane proteins promote recognition by autoantibodies.

    NARCIS (Netherlands)

    Dinkla, S.; Novotny, V.M.J.; Joosten, I.; Bosman, G.J.C.G.M.

    2012-01-01

    Physiological erythrocyte removal is associated with a selective increase in expression of neoantigens on erythrocytes and their vesicles, and subsequent autologous antibody binding and phagocytosis. Chronic erythrocyte transfusion often leads to immunization and the formation of alloantibodies and

  8. Electron paramagnetic resonance study of lipid and protein membrane components of erythrocytes oxidized with hydrogen peroxide

    Energy Technology Data Exchange (ETDEWEB)

    Mendanha, S.A.; Anjos, J.L.V.; Silva, A.H.M.; Alonso, A. [Instituto de Física, Universidade Federal de Goiás, Goiânia, GO (Brazil)

    2012-04-05

    Electron paramagnetic resonance (EPR) spectroscopy of spin labels was used to monitor membrane dynamic changes in erythrocytes subjected to oxidative stress with hydrogen peroxide (H{sub 2}O{sub 2}). The lipid spin label, 5-doxyl stearic acid, responded to dramatic reductions in membrane fluidity, which was correlated with increases in the protein content of the membrane. Membrane rigidity, associated with the binding of hemoglobin (Hb) to the erythrocyte membrane, was also indicated by a spin-labeled maleimide, 5-MSL, covalently bound to the sulfhydryl groups of membrane proteins. At 2% hematocrit, these alterations in membrane occurred at very low concentrations of H{sub 2}O{sub 2} (50 µM) after only 5 min of incubation at 37°C in azide phosphate buffer, pH 7.4. Lipid peroxidation, suggested by oxidative hemolysis and malondialdehyde formation, started at 300 µM H{sub 2}O{sub 2} (for incubation of 3 h), which is a concentration about six times higher than those detected with the probes. Ascorbic acid and α-tocopherol protected the membrane against lipoperoxidation, but did not prevent the binding of proteins to the erythrocyte membrane. Moreover, the antioxidant (+)-catechin, which also failed to prevent the cross-linking of cytoskeletal proteins with Hb, was very effective in protecting erythrocyte ghosts from lipid peroxidation induced by the Fenton reaction. This study also showed that EPR spectroscopy can be useful to assess the molecular dynamics of red blood cell membranes in both the lipid and protein domains and examine oxidation processes in a system that is so vulnerable to oxidation.

  9. Electron paramagnetic resonance study of lipid and protein membrane components of erythrocytes oxidized with hydrogen peroxide

    Directory of Open Access Journals (Sweden)

    S.A. Mendanha

    2012-06-01

    Full Text Available Electron paramagnetic resonance (EPR spectroscopy of spin labels was used to monitor membrane dynamic changes in erythrocytes subjected to oxidative stress with hydrogen peroxide (H2O2. The lipid spin label, 5-doxyl stearic acid, responded to dramatic reductions in membrane fluidity, which was correlated with increases in the protein content of the membrane. Membrane rigidity, associated with the binding of hemoglobin (Hb to the erythrocyte membrane, was also indicated by a spin-labeled maleimide, 5-MSL, covalently bound to the sulfhydryl groups of membrane proteins. At 2% hematocrit, these alterations in membrane occurred at very low concentrations of H2O2 (50 µM after only 5 min of incubation at 37°C in azide phosphate buffer, pH 7.4. Lipid peroxidation, suggested by oxidative hemolysis and malondialdehyde formation, started at 300 µM H2O2 (for incubation of 3 h, which is a concentration about six times higher than those detected with the probes. Ascorbic acid and α-tocopherol protected the membrane against lipoperoxidation, but did not prevent the binding of proteins to the erythrocyte membrane. Moreover, the antioxidant (+-catechin, which also failed to prevent the cross-linking of cytoskeletal proteins with Hb, was very effective in protecting erythrocyte ghosts from lipid peroxidation induced by the Fenton reaction. This study also showed that EPR spectroscopy can be useful to assess the molecular dynamics of red blood cell membranes in both the lipid and protein domains and examine oxidation processes in a system that is so vulnerable to oxidation.

  10. Metallic mercury uptake by catalase Part 1 In Vitro metallic mercury uptake by various kind of animals' erythrocytes and purified human erythrocyte catalase

    OpenAIRE

    劒持,堅志

    1980-01-01

    The uptake of metallic mercury was studied using erythrocytes with different catalase activities taken from various kind of animals. The results were: 1) The uptake of metallic mercury by erythrocytes paralleled the activity of catalase in the erythrocytes with and without hydrogen peroxide, suggesting that the erythrocyte catalase activity is related to the uptake of metallic mercury. 2) The uptake of metallic mercury occurred not only with purified human erythrocyte catalase but also with h...

  11. Erythrocyte aging: a more than superficial resemblance to apoptosis?

    NARCIS (Netherlands)

    Bosman, G.J.C.G.M.; Willekens, F.L.A.; Werre, J.M.

    2005-01-01

    In physiological circumstances, erythrocyte aging leads to binding of autologous IgG followed by recognition and removal through phagocytosis, mainly by Kupffer cells in the liver. This process is triggered by the appearance of a senescent erythrocyte-specific antigen. The functional and structural

  12. Long term storage stabilizes human erythrocyte membrane in ...

    African Journals Online (AJOL)

    Osmotic fragility (OF) test was conducted in Nigerian human black male erythrocytes stored for Oh, 12h, 24h and 48h. Storage of these human erythrocytes for up to 24h failed to alter significantly their membrane characteristics. A leftward shift in osmotic fragiligrams was noted suggestive of storage-time (age) dependent ...

  13. The Role and Mechanism of Erythrocyte Invasion by Francisella tularensis

    Directory of Open Access Journals (Sweden)

    Deanna M. Schmitt

    2017-05-01

    Full Text Available Francisella tularensis is an extremely virulent bacterium that can be transmitted naturally by blood sucking arthropods. During mammalian infection, F. tularensis infects numerous types of host cells, including erythrocytes. As erythrocytes do not undergo phagocytosis or endocytosis, it remains unknown how F. tularensis invades these cells. Furthermore, the consequence of inhabiting the intracellular space of red blood cells (RBCs has not been determined. Here, we provide evidence indicating that residing within an erythrocyte enhances the ability of F. tularensis to colonize ticks following a blood meal. Erythrocyte residence protected F. tularensis from a low pH environment similar to that of gut cells of a feeding tick. Mechanistic studies revealed that the F. tularensis type VI secretion system (T6SS was required for erythrocyte invasion as mutation of mglA (a transcriptional regulator of T6SS genes, dotU, or iglC (two genes encoding T6SS machinery severely diminished bacterial entry into RBCs. Invasion was also inhibited upon treatment of erythrocytes with venom from the Blue-bellied black snake (Pseudechis guttatus, which aggregates spectrin in the cytoskeleton, but not inhibitors of actin polymerization and depolymerization. These data suggest that erythrocyte invasion by F. tularensis is dependent on spectrin utilization which is likely mediated by effectors delivered through the T6SS. Our results begin to elucidate the mechanism of a unique biological process facilitated by F. tularensis to invade erythrocytes, allowing for enhanced colonization of ticks.

  14. Arsenate V induced glutathione efflux from human erythrocytes.

    Science.gov (United States)

    Yildiz, Deniz; Cakir, Yeliz

    2012-01-01

    The objective of the present study was to investigate if arsenate V exposure results in glutathione efflux from human erythrocytes. The changes in intracellular and extracellular nonprotein sulfhydryl and glutathione levels were determined in arsenate (V) exposed erythrocytes. Presence of any cellular membrane damage was assessed by lactate dehydrogenase activity measurement in the supernatant. When erythrocytes were exposed to 10 mM of arsenate (V) for 4 h, the intracellular NPSH level decreased to 0.28±0025 μmol/ml erythrocyte. In contrast, extracellular nonprotein thiol level was increased to 0.180±0.010 μmol/ml erythrocyte in 4 h. Extracellular glutathione levels reached to 0.028±0.001, 0.052±0.002, and 0.054±0.004 μmol/ml erythrocyte with 1, 5, and 10 mM of arsenate (V), respectively. Utilization of MK571 a multi drug resistance-associated protein 1 inhibitor decreased the rate of glutathione efflux from erythrocytes suggesting a role for this membrane transporter in the process. The results of the present study indicate that erythrocytes efflux glutathione when exposed to arsenate (V). Copyright © 2011 Elsevier GmbH. All rights reserved.

  15. Murine erythrocytes contain high levels of lysophospholipase activity

    NARCIS (Netherlands)

    Kamp, J.A.F. op den; Roelofsen, B.; Sanderink, G.; Middelkoop, E.; Hamer, R.

    1984-01-01

    Murine erythrocytes were found to be unique in the high levels of lysophospholipase activity in the cytosol of these cells. The specific activity of the enzyme in the cytosol of the murine cells is 10-times higher than in the cytosol of rabbit erythrocytes and approximately three orders of magnitude

  16. Effect of laser irradiation of donor blood on erythrocyte shape.

    Science.gov (United States)

    Baibekov, I M; Ibragimov, A F; Baibekov, A I

    2012-04-01

    Changes in erythrocyte shape in donor blood during storage and after irradiation with He-Ne laser and infrared laser were studied by scanning electron microscopy, thick drop express-method, and morphometry. It was found that laser irradiation delayed the appearance of erythrocytes of pathological shapes (echinocytes, stomatocytes, etc.) in the blood; He-Ne laser produced a more pronounced effect.

  17. Phenotypic drift in osmotic fragility of Sahel goat erythrocytes ...

    African Journals Online (AJOL)

    Abstract. A typical mammalian erythrocyte fragility phenotype (EFP) exhibits a sigmoidal curve of the dependence of fragilities (% haemolysis) on hypotonic saline concentrations, but the goat EFP tends to be hyperbolic. Physiological variation in median erythrocyte fragility (MEF) and the associated EFP of Sahel goats was ...

  18. Activation of human erythrocyte glutathione – s – transferase (EC ...

    African Journals Online (AJOL)

    ) of the isolated caffeine were tested in-vitro on their possible effect on human erythrocyte (red cell) glutathione – S – transferase (EC. 2.5.1.18) activity. The result indicated significant (P < 0.05) activation of the erythrocyte enzyme (GST) by ...

  19. CD47 functions as a molecular switch for erythrocyte phagocytosis

    NARCIS (Netherlands)

    Burger, Patrick; Hilarius-Stokman, Petra; de Korte, Dirk; van den Berg, Timo K.; van Bruggen, Robin

    2012-01-01

    CD47 on erythrocytes inhibits phagocytosis through interaction with the inhibitory immunoreceptor SIRP alpha expressed by macrophages. Thus, the CD47-SIRP alpha interaction constitutes a negative signal for erythrocyte phagocytosis. However, we report here that CD47 does not only function as a "do

  20. [The effect of low intensity luminescent radiation on erythrocyte membranes].

    Science.gov (United States)

    Monich, V A

    1994-01-01

    It was found that luminescent monochromatized incoherent radiation causes inhibition of the ultraviolet light-induced hemolysis of erythrocytes comparable to that induced by laser light. The obtained data show reduction of the molecular product rate of free radical fat acyclic oxidation in the membranes of intact erythrocytes after irradiation by low intensity red light.

  1. The clinical importance of erythrocyte deformability, a hemorrheological parameter

    NARCIS (Netherlands)

    Mokken, F. C.; Kedaria, M.; Henny, C. P.; Hardeman, M. R.; Gelb, A. W.

    1992-01-01

    Hemorheology, the science of the flow behavior of blood, has become increasingly important in clinical situations. The rheology of blood is dependent on its viscosity, which in turn is influenced by plasma viscosity, hematocrit, erythrocyte aggregation, and erythrocyte deformability. In recent years

  2. Preferential Elimination of Older Erythrocytes in Circulation and Depressed Bone Marrow Erythropoietic Activity Contribute to Cadmium Induced Anemia in Mice.

    Science.gov (United States)

    Chatterjee, Sreoshi; Saxena, Rajiv K

    2015-01-01

    Feeding cadmium chloride (50 or 1000 ppm CdCl2 in drinking water, ad libitum) to C57BL/6 mice resulted in a significant and sustained fall in blood erythrocyte count and hemoglobin levels that started 4 and 3 weeks after the start of 50 and 1000 ppm cadmium doses respectively. A transient yet significant reticulocytosis occurred during the first 4 weeks of cadmium treatment. Using the recently developed double in vivo biotinylation (DIB) technique, turnover of erythrocyte cohorts of different age groups was simultaneously monitored in control and cadmium treated mice. A significant accumulation of younger erythrocytes and a concomitant decline in the relative proportions of older erythrocytes in circulation was observed in both 50 and 1000 ppm cadmium groups indicating that older erythrocytes were preferentially eliminated in cadmium induced anemia. A significant increase in the erythropoietin levels in plasma was seen in mice exposed to 1000 ppm cadmium. Levels of inflammatory cytokines (IL1A, IL6, TNFα, IFNγ) were however not significantly altered in cadmium treated mice. A significant increase in cellular levels of reactive oxygen species (ROS) was observed in older erythrocytes in circulation but not in younger erythrocytes. Erythropoietic activity in the bone marrows and spleens of cadmium treated mice was examined by monitoring the relative proportion of cells belonging to the erythroid line of differentiation in these organs. Erythroid cells in bone marrow declined markedly (about 30%) in mice in the 1000 ppm cadmium group but the decline was not significant in the 50 ppm cadmium group. Cells representing various stages of erythroid differentiation in bone marrow and spleen were enumerated flow cytometrically by double staining with anti-Ter119 and anti-transferrin receptor (CD71) monoclonal antibodies. Decline of erythroid cells was essentially confined to pro-erythroblast and erythroblast-A, along with a concurrent increase in the splenic erythroid

  3. Migraine and erythrocyte biology: a review.

    Science.gov (United States)

    Lippi, G; Cervellin, G; Mattiuzzi, C

    2014-12-01

    Migraine is a common disabling headache disorder that is conventionally classified according to the presence or absence of aura. The pathogenesis of this disorder entails a complex interplay of neurovascular factors, that trigger reduction of cerebral blood flow followed by reactive vasodilatation. Despite major emphasis has been placed on the investigation of putative biomarkers that could predict response to specific treatments and prophylaxis, less focus has been directed at the association between migraine and erythrocytosis. Erythrocytosis is typically accompanied by hyperviscosity, that is now considered a crucial determinant in the pathogenesis of migraine. The results of some epidemiological investigations are in substantial agreement to confirm the existence of a significant relationship between increased haemoglobin levels and migraine, whereas some case reports have also reported an effective improvement of symptoms after reduction of erythrocyte count by therapeutic venesection. Interesting evidence has recently emerged from the assessment of red blood cell distribution width (RDW), a simple and inexpensive measure of anysocytosis that has been also associated with a variety of ischaemic and thrombotic disorders other than migraine. The aim of this review was to provide an overview of the current clinical and epidemiological evidence linking migraine and erythrocyte biology. © 2014 John Wiley & Sons Ltd.

  4. Mitoxantrone-Induced Suicidal Erythrocyte Death

    Directory of Open Access Journals (Sweden)

    Markus Arnold

    2014-11-01

    Full Text Available Background/Aims: Mitoxantrone, a cytotoxic drug used for the treatment of malignancy and multiple sclerosis, is at least in part effective by triggering apoptosis. Similar to apoptosis of nucleated cells, erythrocytes may enter eryptosis, a type of suicidal cell death. Hallmarks of eryptosis are cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Signalling involved in eryptosis include Ca2+-entry, ceramide formation and oxidative stress. Methods: Cell volume was estimated from forward scatter, phosphatidylserine-exposure from annexin V binding, formation of reactive oxidant species (ROS from 2′,7′-dichlorodihydrofluorescein-diacetate fluorescence, and ceramide abundance from binding of fluorescent antibodies in flow cytometry. Results: A 48 hours exposure to mitoxantrone was followed by significant decrease of forward scatter (≥ 5 μg/ml mitoxantrone and increase of annexin-V-binding (≥ 10 μg/ml mitoxantrone, effects paralleled by significant increases of ROS formation (25 μg/ml mitoxantrone and ceramide abundance (25 μg/ml mitoxantrone. The effect of mitoxantrone was not significantly modified by nominal absence of extracellular Ca2+ but significantly blunted by the antioxidant N-acetylcysteine (1 mM. Conclusions: Mitoxantrone triggers cell membrane scrambling, an effect not requiring entry of extracellular Ca2+ but at least partially due to formation of ROS and ceramide.

  5. Binding characteristics of swine erythrocyte insulin receptors

    Energy Technology Data Exchange (ETDEWEB)

    Dieberg, G.; Bryan, G.S.; Sartin, J.L.; Williams, J.C.; Prince, T.J.; Kemppainen, R.J.

    1985-09-01

    Crossbred gilts had 8.8 +/- 1.1% maximum binding of ( SVI)insulin to insulin receptors on erythrocytes. The number of insulin-binding sites per cell was 137 +/- 19, with a binding affinity ranging from 7.4 X 10(7)M-1 to 11.2 X 10(7)M-1 and mean of 8.8 X 10(7)M-1. Pregnant sows had a significant increase in maximum binding due to an increase in number of receptor sites per cell. Lactating sows fed a high-fiber diet and a low-fiber diet did not develop a significant difference in maximum binding of insulin. Sows fed the low-fiber diet had a significantly higher number of binding sites and a significantly lower binding affinity than did sows fed a high-fiber diet. Receptor-binding affinity was lower in the low-fiber diet group than in cycling gilts, whereas data from sows fed the high-fiber diet did not differ from data for cycling gilts. Data from this study indicated that insulin receptors of swine erythrocytes have binding characteristics similar to those in other species. Pregnancy and diet will alter insulin receptor binding in swine.

  6. Plasmodium falciparum secretome in erythrocyte and beyond

    Directory of Open Access Journals (Sweden)

    Rani eSoni

    2016-02-01

    Full Text Available Plasmodium falciparum is the causative agent of deadly malaria disease. It is an intracellular eukaryote and completes its multi-stage life cycle spanning the two hosts viz, mosquito and human. In order to habituate within host environment, parasite conform several strategies to evade host immune responses such as surface antigen polymorphism or modulation of host immune system and it is mediated by secretion of proteins from parasite to the host erythrocyte and beyond, collectively known as, malaria secretome. In this review, we will discuss about the deployment of parasitic secretory protein in mechanism implicated for immune evasion, protein trafficking, providing virulence, changing permeability and cyto-adherence of infected erythrocyte. We will be covering the possibilities of developing malaria secretome as a drug/vaccine target. This gathered information will be worthwhile in depicting a well-organized picture for host-pathogen interplay during the malaria infection and may also provide some clues for development of novel anti-malarial therapies.

  7. Plasmodium falciparum STEVOR proteins impact erythrocyte mechanical properties

    Science.gov (United States)

    Sanyal, Sohini; Egée, Stéphane; Bouyer, Guillaume; Perrot, Sylvie; Safeukui, Innocent; Bischoff, Emmanuel; Buffet, Pierre; Deitsch, Kirk W.; Mercereau-Puijalon, Odile; David, Peter H.

    2012-01-01

    Infection of erythrocytes with the human malaria parasite, Plasmodium falciparum, results in dramatic changes to the host cell structure and morphology. The predicted functional localization of the STEVOR proteins at the erythrocyte surface suggests that they may be involved in parasite-induced modifications of the erythrocyte membrane during parasite development. To address the biologic function of STEVOR proteins, we subjected a panel of stevor transgenic parasites and wild-type clonal lines exhibiting different expression levels for stevor genes to functional assays exploring parasite-induced modifications of the erythrocyte membrane. Using this approach, we show that stevor expression impacts deformability of the erythrocyte membrane. This process may facilitate parasite sequestration in deep tissue vasculature. PMID:22106347

  8. Erythrocyte selenium concentration as a marker of selenium status.

    Science.gov (United States)

    Stefanowicz, Fiona A; Talwar, Dinesh; O'Reilly, Denis S J; Dickinson, Natalie; Atkinson, John; Hursthouse, Andrew S; Rankin, Jean; Duncan, Andrew

    2013-10-01

    Plasma selenium concentration and glutathione peroxidase (GPx) activity are commonly used as markers of selenium nutritional status. However, plasma selenium concentrations fall independently of selenium status during the acute phase response and GPx is analytically problematic. The assay for erythrocyte selenium is robust and concentrations are unaffected by the systemic inflammatory response. This study was performed to investigate the validity of erythrocyte selenium measurement in assessing selenium status. C-reactive protein (CRP), plasma and erythrocyte selenium concentrations and GPx activity were measured in 96 women from two regions of Malawi with low and high selenium dietary intakes. CRP and plasma and erythrocyte selenium was measured in 91 critically ill patients with a systemic inflammatory response. The median CRP value of all subjects from Malawi was 4.2 mg/L indicating no inflammation. The median CRP value for the critically ill patients was 126 mg/L indicating this group was inflamed. In the non-inflamed population there was a strong positive correlation (r = 0.95) between erythrocyte and plasma selenium and a strong positive correlation (r = 0.77) between erythrocyte selenium and erythrocyte GPx up to 6.10 nmol/g Hb after which maximal activity was reached. In the inflamed population, plasma selenium was low, erythrocyte selenium was normal and there was a weak correlation (r = 0.30) between selenium concentrations in plasma and erythrocytes. This demonstrates that plasma selenium is affected by the inflammatory response while erythrocyte selenium concentration is unaffected and can be used to reliably assess selenium status across a wide range of selenium intakes. Copyright © 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  9. Synergistic Effect of Rapamycin and Metformin Against Age-Dependent Oxidative Stress in Rat Erythrocytes.

    Science.gov (United States)

    Singh, Abhishek Kumar; Garg, Geetika; Singh, Sandeep; Rizvi, Syed Ibrahim

    2017-10-01

    Erythrocytes are particularly vulnerable toward age-dependent oxidative stress-mediated damage. Caloric restriction mimetics (CRMs) may provide a novel strategy for the maintenance of redox balance as well as effective treatment of age-associated diseases. Herein, we have investigated the beneficial effect of cotreatment with CRM-candidate drugs, rapamycin (an immunosuppressant drug and inhibitor of mammalian target of rapamycin) and metformin (an antidiabetic biguanide and activator of adenosine monophosphate kinase), against aging-induced oxidative stress in erythrocytes and plasma of aging rats. Male Wistar rats of age 4 (young) and 24 months (old) were coexposed to rapamycin (0.5 mg/kg body weight [b.w.]) and metformin (300 mg/kg b.w.), and data were compared with the response of rats receiving an independent exposure to these chemicals at similar doses. The exposure of individual candidate drugs significantly reversed the age-dependent alterations in the endpoints associated with oxidative stress such as reactive oxygen species, ferric reducing ability of plasma, malondialdehyde, reduced glutathione, plasma membrane redox system, plasma protein carbonyl, and acetyl cholinesterase in erythrocytes and plasma of aging rats. However, the cotreatment with rapamycin and metformin showed a significant augmented effect compared with individual drug interventions on reversal of these age-dependent biomarkers of oxidative stress, suggesting a synergistic response. Thus, the findings open up further possibilities for the design of new combinatorial therapies to prevent oxidative stress- and age-associated health problems.

  10. Erythrocyte diagnosticum as used in revealingmalignant process

    Directory of Open Access Journals (Sweden)

    L. A. Savluchinskayа

    2017-01-01

    Full Text Available A method is proposed for the development of an erythrocyte diagnosticum based on the evidence of patent № 2452501 (10.06.2012 via development of sensitine obtained from the serum of mares in foal, the above factor being used for diagnosis of malignant neoplasms. In order  to reveal the practical significance of the diagnosticum proposed the findings of the testing of the blood serum of 215 patients with variously located tumors and from 67 individuals without malignant tumors are analyzed. Sensitivity of the method was 88 %, specificity – 89 %,  accuracy – 89 %. The accessibility of the method proposed and simplicity of the reaction as well as the rapid response make it possible to use the method under discussion in any medical institution individually or in the course of screening to obtain primary diagnosis or to reveal risk groups.

  11. Deformability of Erythrocytes and Oxidative Damage in Alzheimer Disease

    Directory of Open Access Journals (Sweden)

    Mukerrem Betul Yerer

    2012-04-01

    Full Text Available Purpose: A lowered cerebral perfusion as a consequence of hemodynamic microcirculatory insufficiency is one of the factors underlying in Alzheimer's disease, which is a neurodegenerative disorder leading to progressive cognitive impairment. Erythrocyte deformability is one of the major factors affecting the microcirculatory hemodynamics which is closely related to the oxidative damage. The aim of this study is to investigate the relationship between the erythrocyte deformability, nitric oxide levels and oxidative stress in Alzheimer's disease. Methods: The blood samples of 30 elderly people in three groups consisting of healthy control and different severities of the disease (low and severe were used. Then the erythrocytes were isolated and the deformability of erythrocytes was determined by Rheodyne SSD evaluating the elongation indexes of the erythrocytes under different shear stress. The catalase, glutathione peroxidase and plasma nitric oxide levels were measured spectrophotometric ally. Results: The plasma nitric oxide levels, catalase activities were found significantly higher and glutathione peroxidase activity was significantly lower in severe Alzheimer's disease patients compared to the control group. However, the deformability of erythrocytes was not significantly affected from these alterations. Conclusion: the oxidant-antioxidant status is dramatically changed in Alzheimer's disease patients with the severity of the disease and similar alterations were seen in the nitric oxide levels without any significant change in erythrocyte deformability. [Cukurova Med J 2012; 37(2.000: 65-75

  12. Erythrocyte sedimentation rate as a marker for coronary heart disease.

    Science.gov (United States)

    Yayan, Josef

    2012-01-01

    Patients with angina pectoris or myocardial infarction frequently present without evidence of cardiac-specific heart enzymes by laboratory analysis or specific pathologic electro-cardiogram findings. The current study analyzed the efficacy of the erythrocyte sedimentation rate as an additional potential indicator for coronary heart disease, the aim being to enable quicker identification of patients with angina pectoris or myocardial infarction so that they can be more rapidly treated. Patients with angina pectoris or myocardial infarction who had undergone a heart catheter examination were included in the study. The diagnosis of acute coronary heart disease was made by the physician who performed coronary angiography. Patients without coronary heart disease were used as a control group. The erythrocyte sedimentation rate was measured in all patients. Patients with angina pectoris or myocardial infarction and an inflammatory or tumor disease were excluded. The erythrocyte sedimentation rate was prolonged in 79 (58.09%) of 136 patients; 69 (50.74%) patients (95% confidence interval ±8.4%, 42.34%-59.14%) had coronary heart disease and a prolonged erythrocyte sedimentation rate. The erythrocyte sedimentation rate was prolonged in ten (7.35%) patients (95% confidence interval ±4.39%, 2.96%-11.74%) without coronary heart disease by coronary angiography. The specificity of the erythrocyte sedimentation rate for coronary heart disease was 70.59% and the sensitivity was 67.65%. Erythrocyte sedimentation rate may be a useful additional diagnostic criterion for coronary heart disease.

  13. Increased dense erythrocytes in flame-burned patients.

    Science.gov (United States)

    Saavedra, Arturo P; Warth, James A; Burke, John F; Norton, Kathryn J; Gelfand, Jeffrey A

    2013-01-01

    We have studied dense erythrocytes separated on Arabinogalactan (Stractan) ultracentrifuged gradients in flame-burned patients and in normal individuals. In each case, the percentage of erythrocytes in the densest layers was increased when compared to age and sex matched controls. Using an in vitro system, we showed that as human whole blood is warmed to 48.6°C, the number of dense erythrocytes increases. In addition, the reduced glutathionine (GSH) content of the densest red blood cells is decreased compared to those in lighter fractions on the same gradient or to dense erythrocytes separated from blood incubated at room temperature. These dense red cells were largely composed of spherocytes and spheroechynocytes, two forms of erythrocytes which have been shown by others to have markedly abnormal flow characteristics in vitro. We have demonstrated that in vivo dense erythrocytes can be generated in the setting of flame burns. Thus, the underlying reason may be oxidant injury as represented by the reduced level of GSH that we found in association with the generation of dense erythrocytes.

  14. Simulation of the osmosis-based drug encapsulation in erythrocytes.

    Science.gov (United States)

    Ge, Duobiao; Zou, Lili; Li, Chengpan; Liu, Sen; Li, Shibo; Sun, Sijie; Ding, Weiping

    2017-09-20

    Drug-loaded erythrocytes have been proposed for the treatment of disease. A common way to load drugs into erythrocytes is to apply osmotic shock. Currently, osmosis-based drug encapsulation is studied mainly experimentally, whereas a related theoretical model is still incomplete. In this study, a set of equations is developed to simulate the osmosis-based drug-encapsulation process. First, the modeling is validated with hemolysis rates and the drug-loaded quantities to be found in the literature. Then, the variation of the erythrocyte volume, formation of the pore on the erythrocyte membrane, and quantities of drug loaded into and hemoglobin released from erythrocytes are studied. Finally, an optimized operating condition for encapsulating drugs is proposed. The results show that the volume of erythrocytes exposed to hypotonic NaCl solution increases first and then abruptly decreases because of the pore formation; afterwards, it again increases and then decreases slowly. In the presence of the pore, the drug is loaded by diffusion, whereas the leak-induced convection goes against the loading. For an allowed 45% hemolysis rate, with a 10% hematocrit, the optimized NaCl concentration is 0.44%, the optimized time for sealing the loaded erythrocytes with hypertonic NaCl solution is at 6.5 s, and the quantity of albumin (drug) loaded is 4.5 mg/ml cells.

  15. Focusing and alignment of erythrocytes in a viscoelastic medium

    Science.gov (United States)

    Go, Taesik; Byeon, Hyeokjun; Lee, Sang Joon

    2017-01-01

    Viscoelastic fluid flow-induced cross-streamline migration has recently received considerable attention because this process provides simple focusing and alignment over a wide range of flow rates. The lateral migration of particles depends on the channel geometry and physicochemical properties of particles. In this study, digital in-line holographic microscopy (DIHM) is employed to investigate the lateral migration of human erythrocytes induced by viscoelastic fluid flow in a rectangular microchannel. DIHM provides 3D spatial distributions of particles and information on particle orientation in the microchannel. The elastic forces generated in the pressure-driven flows of a viscoelastic fluid push suspended particles away from the walls and enforce erythrocytes to have a fixed orientation. Blood cell deformability influences the lateral focusing and fixed orientation in the microchannel. Different from rigid spheres and hardened erythrocytes, deformable normal erythrocytes disperse from the channel center plane, as the flow rate increases. Furthermore, normal erythrocytes have a higher angle of inclination than hardened erythrocytes in the region near the side-walls of the channel. These results may guide the label-free diagnosis of hematological diseases caused by abnormal erythrocyte deformability.

  16. Lipopeptide-Induced Suicidal Erythrocyte Death Correlates with the Degree of Acylation

    Directory of Open Access Journals (Sweden)

    Abdulla Al Mamun Bhuyan

    2017-01-01

    Full Text Available Background/Aims: Consequences of bacterial infection include anemia, which could result from stimulation of suicidal erythrocyte death or eryptosis, characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Bacterial components known to stimulate eryptosis include lipopeptides. Signaling mediating the triggering of eryptosis include increased cytosolic Ca2+ activity ([Ca2+]i, oxidative stress and cellular accumulation of ceramide. The present study aimed to define the molecular requirements for lipopeptide-induced cell membrane scrambling. Methods: Human erythrocytes were incubated for 48 hours in the absence and presence of 1 or 5 µg/ml of the synthetic lipopeptides Pam1 (lipopeptide with one fatty acid, Pam2 (lipopeptide with two fatty acids, or Pam3 (lipopeptide with three fatty acids. In the following phosphatidylserine exposure at the cell surface was estimated from annexin-V-binding, cell volume from forward scatter, [Ca2+]i from Fluo3-fluorescence, ROS formation from DCF dependent fuorescence, and ceramide abundance utilizing specific antibodies. Results: Pam1 (5 µg/ml, Pam2 (5 µg/ml and Pam3 (1 and 5 µg/ml significantly increased the percentage of annexin-V-binding to erythrocytes in a dose dependent manner, which was largely independent of Ca2+. Pam1-3 increased the percentage of both, swollen and shrunken erythrocytes without significantly modifying the average forward scatter. They also increased reactive oxygen species (ROS and ceramide abundance. In all assays the effect on eryptosis increased with increasing number of fatty acids, with Pam3 showing always the strongest effect. In contrast, a comparison of the effect of Pam1-3 on TLR2 dependent immune stimulation showed that not Pam3 but Pam2 displayed the strongest activity, and that immune stimulation was triggered at much lower concentrations than eryptosis. Conclusions: Lipopeptides are not only important

  17. Erythrocyte Features for Malaria Parasite Detection in Microscopic Images of Thin Blood Smear: A Review

    Directory of Open Access Journals (Sweden)

    Salam Shuleenda Devi

    2016-12-01

    Full Text Available Microscopic image analysis of blood smear plays a very important role in characterization of erythrocytes in screening of malaria parasites. The characteristics feature of erythrocyte changes due to malaria parasite infection. The microscopic features of the erythrocyte include morphology, intensity and texture. In this paper, the different features used to differentiate the non- infected and malaria infected erythrocyte have been reviewed.

  18. Evidence that Clostridium perfringens theta-toxin induces colloid-osmotic lysis of erythrocytes.

    OpenAIRE

    Harris, R. W.; Sims, P J; Tweten, R K

    1991-01-01

    Clostridium perfringens theta-toxin was shown to lyse target erythrocytes by a colloid-osmotic mechanism. Analysis showed the onset of lysis of erythrocytes by theta-toxin could be temporarily stabilized with 0.3 M sucrose. Flow cytometry analysis of the size distribution of theta-toxin-treated erythrocytes showed swelling of the erythrocytes prior to lysis.

  19. Apolipoprotein M mediates sphingosine-1-phosphate efflux from erythrocytes

    DEFF Research Database (Denmark)

    Christensen, Pernille M.; Bosteen, Markus H.; Hajny, Stefan

    2017-01-01

    Sphingosine-1-phosphate (S1P) is a bioactive lipid implicated in e.g. angiogenesis, lymphocyte trafficking, and endothelial barrier function. Erythrocytes are a main source of plasma S1P together with platelets and endothelial cells. Apolipoprotein M (apoM) in HDL carries 70% of plasma S1P, whereas...... 30% is carried by albumin. The current aim was to investigate the role of apoM in export of S1P from human erythrocytes. Erythrocytes exported S1P more efficiently to HDL than to albumin, particularly when apoM was present in HDL. In contrast, export of sphingosine to HDL was unaffected...

  20. Mature Erythrocytes of Iguana iguana (Squamata, Iguanidae Possess Functional Mitochondria.

    Directory of Open Access Journals (Sweden)

    Giuseppina Di Giacomo

    Full Text Available Electron microscopy analyses of Iguana iguana blood preparations revealed the presence of mitochondria within erythrocytes with well-structured cristae. Fluorescence microscopy analyses upon incubation with phalloidin-FITC, Hoechst 33342 and mitochondrial transmembrane potential (Δψm-sensitive probe MitoTracker Red indicated that mitochondria i widely occur in erythrocytes, ii are polarized, and iii seem to be preferentially confined at a "perinuclear" region, as confirmed by electron microscopy. The analysis of NADH-dependent oxygen consumption showed that red blood cells retain the capability to consume oxygen, thereby providing compelling evidence that mitochondria of Iguana erythrocytes are functional and capable to perform oxidative phosphorylation.

  1. Differential actions of proteinases and neuraminidase on mammalian erythrocyte surface and its impact on erythrocyte agglutination by concanavalin A.

    Science.gov (United States)

    Sharma, Savita; Gokhale, Sadashiv M

    2012-12-01

    Action of proteinases viz. trypsin and chymotrypsin, and neuraminidase on intact erythrocyte membrane proteins and glycophorins (sialoglycoproteins) exposed to cell surface and its impact on lectin (concanavalin A)-mediated agglutination were studied in Homo sapiens (human), Capra aegagrus hircus (goat) and Bubalus bubalis (buffalo). Membrane proteins and glycophorins analysis by SDS-PAGE as visualized by coomassie brilliant blue and periodic acid-schiff stains, respectively, and agglutination behaviour revealed marked differences: 1) there were prominent dissimilarities in the number and molecular weights of glycophorins in human, goat and buffalo erythrocyte membranes; 2) proteinase action(s) on human and buffalo erythrocyte surface membrane proteins and glycophorins showed similarity but was found different in goat; 3) significant differences in erythrocyte agglutinability with concanavalin A can be attributed to differences in membrane composition and alterations in the surface proteins after enzyme treatment; 4) a direct correlation was found between degradation of glycophorins and concanavalin A agglutinability; 5) action of neuraminidase specifically indicated the negative role of cell surface sialic acids in determining concanavalin A agglutinability of goat and buffalo erythrocytes, similar to human. Present studies clearly indicate that there are some basic differences in human, goat and buffalo erythrocyte membrane proteins, especially with respect to glycophorins, which determine the concanavalin A-mediated agglutination in enzyme treated erythrocytes.

  2. A method for visualizing surface-exposed and internal PfEMP1 adhesion antigens in Plasmodium falciparum infected erythrocytes

    DEFF Research Database (Denmark)

    Bengtsson, Dominique; Sowa, Kordai M; Salanti, Ali

    2008-01-01

    of intracellular parasite development although the improved detection method indicates that there are differences between different laboratory isolates in the kinetics of accumulation of surface-exposed PfEMP1. CONCLUSION: A sensitive method for labelling surface and internal PfEMP1 with up to three different...... erythrocyte surface PfEMP1 and intracellular PfEMP1, in parasites whose nuclear material is exceptionally well resolved. Primary antibody detection by fluorescence is carried out on the live parasitized erythrocyte. The surface labelled cells are then fixed using paraformaldehyde and permeabilized with a non......-ionic detergent to permit access of antibodies to internal parasite antigens. Differentiation between surface and internal antigens is achieved using antibodies labelled with different fluorochromes and confocal microscopy RESULTS: Surface exposed PfEMP1 is first detectable by antibodies at the trophozoite stage...

  3. Dynamic Regulation of Cell Volume and Extracellular ATP of Human Erythrocytes.

    Directory of Open Access Journals (Sweden)

    M Florencia Leal Denis

    Full Text Available The peptide mastoparan 7 (MST7 triggered in human erythrocytes (rbcs the release of ATP and swelling. Since swelling is a well-known inducer of ATP release, and extracellular (ATPe, interacting with P (purinergic receptors, can affect cell volume (Vr, we explored the dynamic regulation between Vr and ATPe.We made a quantitative assessment of MST7-dependent kinetics of Vr and of [ATPe], both in the absence and presence of blockers of ATP efflux, swelling and P receptors.In rbcs 10 μM MST7 promoted acute, strongly correlated changes in [ATPe] and Vr. Whereas MST7 induced increases of 10% in Vr and 190 nM in [ATPe], blocking swelling in a hyperosmotic medium + MST7 reduced [ATPe] by 40%. Pre-incubation of rbcs with 10 μM of either carbenoxolone or probenecid, two inhibitors of the ATP conduit pannexin 1, reduced [ATPe] by 40-50% and swelling by 40-60%, while in the presence of 80 U/mL apyrase, an ATPe scavenger, cell swelling was prevented. While exposure to 10 μM NF110, a blocker of ATP-P2X receptors mediating sodium influx, reduced [ATPe] by 48%, and swelling by 80%, incubation of cells in sodium free medium reduced swelling by 92%.Results were analyzed by means of a mathematical model where ATPe kinetics and Vr kinetics were mutually regulated. Model dependent fit to experimental data showed that, upon MST7 exposure, ATP efflux required a fast 1960-fold increase of ATP permeability, mediated by two kinetically different conduits, both of which were activated by swelling and inactivated by time. Both experimental and theoretical results suggest that, following MST7 exposure, ATP is released via two conduits, one of which is mediated by pannexin 1. The accumulated ATPe activates P2X receptors, followed by sodium influx, resulting in cell swelling, which in turn further activates ATP release. Thus swelling and P2X receptors constitute essential components of a positive feedback loop underlying ATP-induced ATP release of rbcs.

  4. Micronucleus Test, Nuclear Abnormalities and Accumulation of Cu and Cd on Gambusia affinis (Baird & Girard, 1853)

    OpenAIRE

    Güner, Utku; Dilek, Fulya; Muranlı, Gökalp

    2011-01-01

    In the present work the induction of micronuclei (MNi) and nuclear abnormalities (NAs) in erythrocytes and Cu and Cd accumulation in whole body of Gambusia affinis were studied. Fish were exposed to two different Cu and Cd concentrations, 0.1 ppm and 1 ppm, for 1 and 2 weeks periods and to Cu-Cd combination (0.1 ppm Cu + 0.1 ppm Cd) for 2 weeks period using a semi-static renewal system. Micronucleus and nuclear abnormality analysis were carried out on peripheral blood erythrocytes. When fish...

  5. Study of Erythrocyte Indices, Erythrocyte Morphometric Indicators, and Oxygen-Binding Properties of Hemoglobin Hematoporphyrin Patients with Cardiovascular Diseases

    Directory of Open Access Journals (Sweden)

    Victor V. Revin

    2017-01-01

    Full Text Available The current study investigates the functional state of erythrocytes and indices of the oxygen-binding capacity of hemoglobin in blood samples from healthy donors and from patients with coronary artery disease and myocardial infarction before and after treatment. It has been established that, in cardiovascular diseases, erythrocyte morphology and hemoglobin oxygen-transporting disorders are observed. Standard therapy does not result in the restoration of the structure and properties of erythrocytes. The authors believe that it is necessary for future therapeutic treatment to include preparations other than cardiovascular agents to enhance the capacity of hemoglobin to transport oxygen to the tissues.

  6. The effect of the prior flow velocity on the structural organization of aggregated erythrocytes in the quiescent blood.

    Science.gov (United States)

    Pribush, Alexander; Meyerstein, Dan; Meyerstein, Naomi

    2011-02-01

    Usually, investigations of erythrocyte aggregation at rest are focused on effects of the strength of erythrocyte-erythrocyte attractive interactions and the volume fraction of the cells, whereas the role of prior flow velocity has not been thoroughly investigated. The aim of this study is to fill this gap. The main conclusions extracted from time records of the complex admittance of blood are as follows: (1) Dispersion of blood in a prior flow into discrete aggregates increases the mesh size of network, which, as has been recently shown, is formed in the quiescent blood. (2) If the energy of the flow field is sufficient to prevent the formation of face-to-side intercellular links, so that the dispersed phase consists of linear rouleaux, changes in the mesh size correlate positively with the length of rouleaux. (3) At slower prior flow velocities, the cells are combined into branched aggregates. As the degree of branching increases, the effect becomes less important. (4) The effects of the length of linear rouleaux and the degree of branching of ramified aggregates on the mesh size are qualitatively similar for suspensions with different aggregating media. (5) Erythrocytes suspended in strongly aggregating media form at low flow conditions a network-like structure. In this case, unlike high and moderate prior flow regimes, the mesh size of RBC network at rest is less than that formed after the stoppage of completely dispersed blood. Copyright © 2010 Elsevier B.V. All rights reserved.

  7. Protective Effect of Sundakai (Solanum torvum) Seed Protein (SP) Against Oxidative Membrane Damage in Human Erythrocytes.

    Science.gov (United States)

    Sivapriya, M; Gowda, S S Thammanna; Srinivas, Leela

    2015-12-01

    Lipid peroxidation by ROS at the membrane level disturbs the inherit integrity of components activating subsequent alterations in the function. In this study, the protective effect of purified Sundakai (Solanum torvum) seed protein (SP) was tested against oxidative membrane damage in erythrocyte membrane. SP prevented oxidative RBC lysis induced by pro-oxidants; Fe:As (2:20 μmol), periodate (0.4 mM), and t-BOOH (1 mM) up to 86, 81, and 86 %, respectively. Further, SP prevented the Fe:As-induced K(+) leakage up to the tune of 95 %. The inhibition offered by SP on K(+) leakage was comparable to inhibition offered by quinine sulfate, a known K(+) channel blocker. SP dose dependently restored Na(+)K(+) ATPase and Ca(2+)Mg(2+) ATPase activities in erythrocyte membrane. The restoration of ATPase activity by SP was two times more than standard antioxidants BHA and α-tocopherol. Besides, SP at 1.6 μmol restored the membrane proteins over Fe:As induction when analyzed by SDS-PAGE, which was comparable to protection offered by BHA. In conclusion, SP is an effective antioxidant in preventing oxidative membrane damage and associated functions mediated by ROS. As SP is non-toxic, it can be used as an effective bioprotective antioxidant agent to cellular components.

  8. Membrane function alterations in erythrocytes from mood disorder ...

    African Journals Online (AJOL)

    mole: mole) ratio and the altered temperature-dependent activity coefficients of erythrocyte membrane AChE and elevated plasma BChE activities could serve as useful diagnostic pointers for mood disorders. Keywords:Membrane function ...

  9. Subcutaneous administration of carrier erythrocytes: slow release of entrapped agent

    Energy Technology Data Exchange (ETDEWEB)

    DeLoach, J.R.; Corrier, D.E.

    1988-08-01

    Carrier erythrocytes administered subcutaneously in mice release encapsulated molecules at the injection site and through cells that escape the injection site. One day postinjection, the efflux of encapsulated (/sup 14/C)sucrose, (/sup 3/H)inulin, and /sup 51/Cr-hemoglobin from the injection site was 45, 55, and 65%, respectively. Intact carrier erythrocytes escaped the injection site and entered the blood circulation carrying with them the encapsulated molecules. Most of the encapsulated (/sup 3/H)inulin that reached whole blood circulated within erythrocytes. Small but measurable numbers of encapsulated molecules were trapped within lymph nodes. Subcutaneous injection of carrier erythrocytes may allow for limited extravascular tissue targeting of drugs.

  10. Erythrocyte oxidative stress markers in children with sickle cell disease

    Directory of Open Access Journals (Sweden)

    Priscila Bacarin Hermann

    2016-07-01

    Conclusions: Oxidative stress parameters in children's erythrocytes were determined using simple laboratory methods with small volumes of blood; these biomarkers can be useful to evaluate disease progression and outcomes in patients.

  11. Cryo scanning electron microscopy of Plasmodium falciparum-infected erythrocytes.

    Science.gov (United States)

    Hempel, Casper

    2017-07-01

    Plasmodium falciparum invades erythrocytes as an essential part of their life cycle. While living inside erythrocytes, the parasite remodels the cell's intracellular organization as well as its outer surface. Late trophozoite-stage parasites and schizonts introduce numerous small protrusions on the erythrocyte surface, called knobs. Current methods for studying these knobs include atomic force microscopy and electron microscopy. Standard electron microscopy methods rely on chemical fixation and dehydration modifying cell size. Here, a novel method is presented using rapid freezing and scanning electron microscopy under cryogenic conditions allowing for high resolution and magnification of erythrocytes. This novel technique can be used for precise estimates of knob density and for studies on cytoadhesion. © 2017 APMIS. Published by John Wiley & Sons Ltd.

  12. [VISCOELASTISITY AND ELECTRICAL PARAMETERS OF ERYTHROCYTES IN GILBERT SYNDROME].

    Science.gov (United States)

    Kurilovich, S A; Nemtsova, E G; Kruchinina, M V; Maximov, V N

    2015-01-01

    Results of viscoelastic and electrical properties of erythrocytes study in patients with genetically confirmed Gilbert's syndrome (n = 81) are presented. Dielectrophoresis of erythrocytes in a nonuniform an alterning electric field was performed in81 patients with Gilbert's syndrome and in 20 persons of the comparison group without of the pathology identified by thelaboratory and instrumental examination. The significant differences in viscoelasticity properties of erythrocytes in Gilbert'ssyndrome were obtained. The amplitude of the deformation, the speed of movement to the electrodes and the polarizability on electric field's of all frequencies were significantly lower, but generalized rigidity index, viscosity, index of aggregationand degradation on electric field's of all frequencies were higher than in the comparison group. A number of electricalparameters (conductivity, the capacity of the cells and the relative polarizability) were also higher than in the comparisongroup. Some differences in the parameters of erythrocytes were obtained from homozygous and heterozygous carriers of A(TA), TAA of gene UGT1A1 promotor.

  13. [Erythrocyte membrane in Duchenne muscular dystrophy. III. Modifications of acetylcholinesterase].

    Science.gov (United States)

    Campagnoli, P; Leporoni, B; Bravi, S; Lenaz, G

    1980-12-15

    Membrane-bound acetylcholinesterase was assayed in erythrocyte ghosts from patients with Duchenne Muscular Distrophy and from the members of their family. Modifications was observed both in Km and Vmax, indicating changes in conformations of the enzyme.

  14. Transbilayer movement of various phosphatidylcholine species in intact human erythrocytes

    OpenAIRE

    van Meer, G.; op den Kamp, J.A.F.

    1982-01-01

    Phosphatidylcholine specific phospholipid exchange protein was used to introduce (14C)-labeled phosphatidylcholine of different fatty acyl compositions into the intact human erythrocyte. Hydrolysis by a combination of phospholipase A2 and sphingomyelinase was applied to prove that originally all newly introduced phosphatidylcholine resided in the outer monolayer. Subsequently the erythrocytes were reincubated at 37°C, and redistribution of the introduced (14C)phosphatidylcholine was monitored...

  15. Insulin causes insulin-receptor internalization in human erythrocyte ghosts.

    OpenAIRE

    Kelleher, R S; Murray, E F; Peterson, S W

    1987-01-01

    The effect of incubation with insulin on insulin-receptor internalization by erythrocyte ghosts was investigated. The number of surface insulin receptors decreased by 30-40% after incubation of ghosts with insulin. Total insulin-receptor binding to solubilized ghosts was the same in insulin-incubated and control ghosts, whereas insulin binding to an internal vesicular fraction was substantially increased in insulin-incubated ghosts. Our findings suggest that erythrocyte-ghost insulin receptor...

  16. [Comparative estimation of morphofunction characteristics alive and fixed erythrocytes].

    Science.gov (United States)

    Skorkina, M Iu; Fedorova, M Z; Cherniavskikh, S D; Zabiniakov, N A; Sladkova, E A

    2011-01-01

    The method of power spectroscopy carries out the quantitative analysis of elastic properties of alive cells. It has been established that the highest indicators of elasticity nuclear (amphibious) and denuclearized (mammals) alive erythrocytes are registered in epi- and perinuclear space. When fixing with methanol and drying of cells the greatest values of the elastic modulus are displaced to the periphery of the cells. The revealed inversion of elasticity properties of erythrocytes must be considered when assessing the morphofunction characteristics of the fixed cells.

  17. Low toxicity method of inhibiting sickling of sickle erythrocytes

    Science.gov (United States)

    Packer, Lester; Bymun, Edwin N.

    1977-01-01

    A low toxicity method of inhibiting sickling of sickle erythrocytes which comprises intermixing the erythrocytes with an effective anti-sickling amount of a water-soluble imidoester of the formula RC(=NH)OR' wherein R is an alkyl group of 1 - 8 carbon atoms, particularly 1 - 4 carbon atoms, and R' is an alkyl group of 1 - 4 carbon atoms, specifically methyl or ethyl acetimidate.

  18. Insulin binding to erythrocytes after acute 16-methyleneprednisolone ingestion.

    Science.gov (United States)

    Dwenger, A; Holle, W; Zick, R; Trautschold, I

    1982-10-01

    The binding of [125I]insulin to erythrocytes, glucose and insulin were determined before and 1, 7 and 35 days after ingestion of 2 X 60-methyleneprednisolone. None of two groups of volunteers (7 males, 4 females showed clear alterations of the insulin binding parameters (Ka and R0), or of the fasting cortisol, glucose and insulin concentrations. These results exclude the possibility that the diabetogenic effect of glucocorticoides is accompanied by an alteration of the insulin receptor characteristics of erythrocytes.

  19. alpha(1)-Adrenoceptor antagonists prevent paracetamol-induced hepatotoxicity in mice.

    Science.gov (United States)

    Randle, L E; Sathish, J G; Kitteringham, N R; Macdonald, I; Williams, D P; Park, B K

    2008-02-01

    Paracetamol, a major cause of acute liver failure (ALF) represents a significant clinical problem. Adrenoceptor stimulation or antagonism can modulate chemical-induced hepatotoxicity. We investigated the role of endogenous catecholamines and alpha(1)-adrenoceptors in the development of paracetamol- induced hepatotoxicity. Paracetamol (3.5 mmol kg(-1)) was administered to male CD-1 mice, with and without alpha(1)-adrenoceptor antagonists (prazosin, doxazosin, terazosin and tamsulosin; 35.7 micromol kg(-1)). Serum transaminases and hepatic glutathione (GSH) levels were assessed as markers of hepatic damage. Paracetamol bioactivation was assessed by covalent binding, hepatic and urinary conjugate formation and uridine glucuronosyltransferase activity. Plasma catecholamines levels and hepatic congestion were also analysed. Plasma catecholamine levels were significantly elevated 5 h post paracetamol administration. Prazosin prevented hepatotoxicity when administered 1 h before a toxic paracetamol insult and importantly, when administered up to 1 h post paracetamol injection. Prazosin had no effect on paracetamol-induced depletion of hepatic GSH, paracetamol bioactivation or paracetamol-induced transcription of defence genes. Paracetamol toxicity is associated with marked accumulation of erythrocytes within hepatic sinusoids and prazosin completely prevented this accumulation. Paracetamol-induced hepatocellular damage is associated with increased circulating catecholamines. alpha(1)-Adrenoceptor antagonists conferred complete protection from paracetamol -induced hepatotoxicity. Protection was associated with absence of hepatic erythrocyte accumulation. Increased catecholamine levels may contribute to the pathophysiology of paracetamol-induced hepatotoxicity by compromising hepatic perfusion. Protection against paracetamol toxicity by alpha(1) antagonists in mice has implications for therapeutic management of patients presenting with paracetamol overdose and ALF.

  20. AMPKα1 Deletion Shortens Erythrocyte Life Span in Mice

    Science.gov (United States)

    Wang, Shaobin; Dale, George L.; Song, Ping; Viollet, Benoit; Zou, Ming-hui

    2010-01-01

    AMP-activated protein kinase (AMPK) is an energy sensor essential for maintaining cellular energy homeostasis. Here, we report that AMPKα1 is the predominant isoform of AMPK in murine erythrocytes and mice globally deficient in AMPKα1 (AMPKα1−/−), but not in those lacking AMPKα2, and the mice had markedly enlarged spleens with dramatically increased proportions of Ter119-positive erythroid cells. Blood tests revealed significantly decreased erythrocyte and hemoglobin levels with increased reticulocyte counts and elevated plasma erythropoietin concentrations in AMPKα1−/− mice. The life span of erythrocytes from AMPKα1−/− mice was less than that in wild-type littermates, and the levels of reactive oxygen species and oxidized proteins were significantly increased in AMPKα1−/− erythrocytes. In keeping with the elevated oxidative stress, treatment of AMPKα1−/− mice with the antioxidant, tempol, resulted in decreased reticulocyte counts and improved erythrocyte survival. Furthermore, the expression of Foxo3 and reactive oxygen species scavenging enzymes was significantly decreased in erythroblasts from AMPKα1−/− mice. Collectively, these results establish an essential role for AMPKα1 in regulating oxidative stress and life span in erythrocytes. PMID:20392689

  1. Stimulation of Suicidal Erythrocyte Death by the Antimalarial Drug Mefloquine

    Directory of Open Access Journals (Sweden)

    Rosi Bissinger

    2015-07-01

    Full Text Available Background: The antimalarial drug mefloquine has previously been shown to stimulate apoptosis of nucleated cells. Similar to apoptosis, erythrocytes may enter suicidal death or eryptosis, which is characterized by cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane with phosphatidylserine translocation to the erythrocyte surface. Stimulators of eryptosis include oxidative stress, increase of cytosolic Ca2+-activity ([Ca2+]i, and ceramide. Methods: Phosphatidylserine abundance at the cell surface was estimated from annexin V binding, cell volume from forward scatter, reactive oxidant species (ROS from 2′,7′-dichlorodihydrofluorescein diacetate (DCFDA fluorescence, [Ca2+]i from Fluo3-fluorescence, and ceramide abundance from specific antibody binding. Results: A 48 h treatment of human erythrocytes with mefloquine significantly increased the percentage of annexin-V-binding cells (≥5 µg/ml, significantly decreased forward scatter (≥5 µg/ml, significantly increased ROS abundance (5 µg/ml, significantly increased [Ca2+]i (7.5 µg/ml and significantly increased ceramide abundance (10 µg/ml. The up-regulation of annexin-V-binding following mefloquine treatment was significantly blunted but not abolished by removal of extracellular Ca2+. Even in the absence of extracellular Ca2+, mefloquine significantly increased annexin-V-binding. Conclusions: Mefloquine treatment leads to erythrocyte shrinkage and erythrocyte membrane scrambling, effects at least partially due to induction of oxidative stress, increase of [Ca2+]i and up-regulation of ceramide abundance.

  2. Platelet inhibition by nitrite is dependent on erythrocytes and deoxygenation.

    Directory of Open Access Journals (Sweden)

    Sirada Srihirun

    Full Text Available Nitrite is a nitric oxide (NO metabolite in tissues and blood, which can be converted to NO under hypoxia to facilitate tissue perfusion. Although nitrite is known to cause vasodilation following its reduction to NO, the effect of nitrite on platelet activity remains unclear. In this study, the effect of nitrite and nitrite+erythrocytes, with and without deoxygenation, on platelet activity was investigated.Platelet aggregation was studied in platelet-rich plasma (PRP and PRP+erythrocytes by turbidimetric and impedance aggregometry, respectively. In PRP, DEANONOate inhibited platelet aggregation induced by ADP while nitrite had no effect on platelets. In PRP+erythrocytes, the inhibitory effect of DEANONOate on platelets decreased whereas nitrite at physiologic concentration (0.1 µM inhibited platelet aggregation and ATP release. The effect of nitrite+erythrocytes on platelets was abrogated by C-PTIO (a membrane-impermeable NO scavenger, suggesting an NO-mediated action. Furthermore, deoxygenation enhanced the effect of nitrite as observed from a decrease of P-selectin expression and increase of the cGMP levels in platelets. The ADP-induced platelet aggregation in whole blood showed inverse correlations with the nitrite levels in whole blood and erythrocytes.Nitrite alone at physiological levels has no effect on platelets in plasma. Nitrite in the presence of erythrocytes inhibits platelets through its reduction to NO, which is promoted by deoxygenation. Nitrite may have role in modulating platelet activity in the circulation, especially during hypoxia.

  3. Differential uptake of cholesterol and plant sterols by rat erythrocytes in vitro.

    Science.gov (United States)

    Child, P; Kuksis, A

    1982-10-01

    The in vitro uptake of radioactively labeled cholesterol and the plant sterol beta-sitosterol has been examined in rat erythrocytes. From mixed micellar solutions containing egg yolk phospholipid and sodium taurocholate, the erythrocytes showed a nonlinear uptake of the two sterols. The uptake leveled off after about 45 min with the attainment of a 1:1 total sterol-to-phospholipid ratio within the cell membrane, as determined on a mass basis. From solutions containing egg yolk phospholipid, or purified egg yolk phosphatidylcholine, a preference for cholesterol over the plant sterol was observed, increasing with time from a cholesterol/beta-sitosterol uptake ratio of unity (the media ratio) to a maximum of 2 after a 60-min incubation. Correction of the data for nonspecifically bound sterol increased the ratio to a maximum of 5 at the 30-min time point. The increase in the cholesterol/beta-sitosterol uptake ratio with time, following an initial nonspecific association, showed that penetration of the plasma membrane by the sterol was required for the selectivity to be expressed. The presence of lysophosphatidylcholine or bovine serum albumin did not exert any noticeable influence over the extent or selectivity of absorption. Replacement of the egg yolk phospholipid with synthetic dipalmitoyl-phosphatidylcholine led to a loss of the sterol selectivity. No evidence was found to support a selective extraction of sterol from the erythrocyte membrane to account for the observed effects, nor was there any sign of a mass accumulation of phospholipid during the incubation. It is suggested that the media phospholipid influences the membrane permeability toward cholesterol and beta-sitosterol.

  4. α2-Macroglobulin Can Crosslink Multiple Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) Molecules and May Facilitate Adhesion of Parasitized Erythrocytes

    DEFF Research Database (Denmark)

    Stevenson, Liz; Laursen, Erik; Cowan, Graeme J

    2015-01-01

    Rosetting, the adhesion of Plasmodium falciparum-infected erythrocytes to uninfected erythrocytes, involves clonal variants of the parasite protein P. falciparum erythrocyte membrane protein 1 (PfEMP1) and soluble serum factors. While rosetting is a well-known phenotypic marker of parasites assoc...

  5. Diabetic Erythrocytes Test by Correlation Coefficient

    Science.gov (United States)

    Korol, A.M; Foresto, P; Darrigo, M; Rosso, O.A

    2008-01-01

    Even when a healthy individual is studied, his/her erythrocytes in capillaries continually change their shape in a synchronized erratic fashion. In this work, the problem of characterizing the cell behavior is studied from the perspective of bounded correlated random walk, based on the assumption that diffractometric data involves both deterministic and stochastic components. The photometric readings are obtained by ektacytometry over several millions of shear elongated cells, using a home-made device called Erythrodeformeter. We have only a scalar signal and no governing equations; therefore the complete behavior has to be reconstructed in an artificial phase space. To analyze dynamics we used the technique of time delay coordinates suggested by Takens, May algorithm, and Fourier transform. The results suggest that on random-walk approach the samples from healthy controls exhibit significant differences from those from diabetic patients and these could allow us to claim that we have linked mathematical nonlinear tools with clinical aspects of diabetic erythrocytes’ rheological properties. PMID:19415139

  6. Escherichia coli α-hemolysin triggers shrinkage of erythrocytes via K(Ca)3.1 and TMEM16A channels with subsequent phosphatidylserine exposure

    DEFF Research Database (Denmark)

    Skals, Marianne Gerberg; Jensen, Uffe Birk; Ousingsawat, Jiraporn

    2010-01-01

    -34 prevent the shrinkage and potentiate hemolysis produced by HlyA. Notably, the recently described Ca(2+)-activated Cl(-) channel TMEM16A contributes substantially to HlyA-induced cell volume reduction. Erythrocytes isolated from TMEM16A(-/-) mice showed significantly attenuated crenation......, which depends on Ca(2+)-activated efflux of K(+) via K(Ca)3.1 and Cl(-) via TMEM16A, with subsequent phosphatidylserine exposure. This mechanism might potentially allow HlyA-damaged erythrocytes to be removed from the bloodstream by macrophages and thereby reduce the risk of intravascular hemolysis....

  7. Inhibitory effect of TNF-α on malaria pre-erythrocytic stage development: influence of host hepatocyte/parasite combinations.

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    Nadya Depinay

    Full Text Available BACKGROUND: The liver stages of malaria parasites are inhibited by cytokines such as interferon-γ or Interleukin (IL-6. Binding of these cytokines to their receptors at the surface of the infected hepatocytes leads to the production of nitric oxide (NO and radical oxygen intermediates (ROI, which kill hepatic parasites. However, conflicting results were obtained with TNF-α possibly because of differences in the models used. We have reassessed the role of TNF-α in the different cellular systems used to study the Plasmodium pre-erythrocytic stages. METHODS AND FINDINGS: Human or mouse TNF-α were tested against human and rodent malaria parasites grown in vitro in human or rodent primary hepatocytes, or in hepatoma cell lines. Our data demonstrated that TNF-α treatment prevents the development of malaria pre-erythrocytic stages. This inhibitory effect however varies with the infecting parasite species and with the nature and origin of the cytokine and hepatocytes. Inhibition was only observed for all parasite species tested when hepatocytes were pre-incubated 24 or 48 hrs before infection and activity was directed only against early hepatic parasite. We further showed that TNF-α inhibition was mediated by a soluble factor present in the supernatant of TNF-α stimulated hepatocytes but it was not related to NO or ROI. Treatment TNF-α prevents the development of human and rodent malaria pre-erythrocytic stages through the activity of a mediator that remains to be identified. CONCLUSIONS: Treatment TNF-α prevents the development of human and rodent malaria pre-erythrocytic stages through the activity of a mediator that remains to be identified. However, the nature of the cytokine-host cell-parasite combination must be carefully considered for extrapolation to the human infection.

  8. Morphological characteristics of urine erythrocytes in children with erythrocyturia

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    V.A. Minakova

    2017-09-01

    Full Text Available Background. Nephropathies with erythrocyturia make up about 1/3 of all diseases of the kidneys and the urinary system, and they have some difficulties in differential diagnostics. Quite often, erythrocyturia is the only symptom of these diseases. In connection with this, determination of its origin is an important task in forming the correct diagnosis. Erythrocyturia in most diseases of the lower urinary tract is not accompanied by proteinuria or the presence of cylinders in the urine. The presence of proteinuria (more than 0.3 g/l or 1 g protein in urine per day, along with the appearance of erythrocytic cylinder in the urine sediment, raises suspicion in favor of glomerular or tubular diseases. Glomerular erythrocytes may be detected by means of urea concentration factor (UCF in the urinary sediment as a preliminary test for the determination of the erythrocyturia site. Erythrocytes that pass through the glomerular membrane have a changed form (dysmorphic. Determination of acanthocytes in the urine (ring-shaped erythrocytes with one or several bulges in the form of bubbles of different sizes and types is a more precise criterion of glomerular nephropathy than the presence of dysmorphic erythrocytes. The purpose of the study was to determine the morphological characteristics of urine erythrocytes in children with erythrocyturia, to improve the quality of differential diagnosis. Materials and methods. Determination of the morphological characteristics of urinary erythrocytes using UCF in 73 patients aged 1 to 18 years, of which 45 (61.6 % are patients with hematuric form of glomerulonephritis, 23 (31.5 % — with hereditary nephritis, and 5 (6.8 % — with dysmetabolic nephropathy. Detection of 50 to 80 % of dysmorphic erythrocytes in the urine sediment and finding in urine of more than 5 % of acanthocytes is a highly sensitive and specific diagnostic criterion for glomerular hematuria. Results. In children with a clinical diagnosis

  9. Advanced Glycation-Modified Human Serum Albumin Evokes Alterations in Membrane and Eryptosis in Erythrocytes.

    Science.gov (United States)

    Awasthi, Saurabh; Gayathiri, S K; Ramya, R; Duraichelvan, R; Dhason, A; Saraswathi, N T

    2015-11-01

    Increased burden of advanced glycation end-products (AGEs) in case of hyperglycemic conditions leads to the development of retinopathy, nephropathy, and cardiovascular and neurological disorders such as Alzheimer's disease. AGEs are considered as pro-oxidants, and their accumulation increases the oxidative stress. The prolonged exposure to these AGEs is the fundamental cause of chronic oxidative stress. Abnormal morphology of red blood cells (RBCs) and excessive eryptosis has been observed in diabetes, glomerulonephritis, dyslipidemia, and obesity, but yet the contribution of extracellular AGEs remains undefined. In this study, we investigated the effect of AGEs on erythrocytes to determine their impact on the occurrence of different pathological forms of these blood cells. Specifically, carboxymethyllysine (CML), carboxyethyllysine (CEL), and Arg-pyrimidine (Arg-P) which have been reported to be the most pre-dominant AGEs formed under in vivo conditions were used in this study. Results suggested the eryptotic properties of CML, CEL, and Arg-P for RBCs, which were evident from the highly damaged cell membrane and occurrence of abnormal morphologies. Methylglyoxal-modified albumin showed more severe effects, which can be attributed to the high reactivity and pro-oxidant nature of glycation end products. These findings suggest the possible role of AGE-modified albumin towards the morphological changes in erythrocyte's membrane associated with diabetic conditions.

  10. SO4= uptake and catalase role in preconditioning after H2O2-induced oxidative stress in human erythrocytes.

    Science.gov (United States)

    Morabito, Rossana; Remigante, Alessia; Di Pietro, Maria Letizia; Giannetto, Antonino; La Spada, Giuseppina; Marino, Angela

    2017-02-01

    Preconditioning (PC) is an adaptive response to a mild and transient oxidative stress, shown for the first time in myocardial cells and not described in erythrocytes so far. The possible adaptation of human erythrocytes to hydrogen peroxide (H2O2)-induced oxidative stress has been here verified by monitoring one of band 3 protein functions, i.e., Cl-/HCO3- exchange, through rate constant for SO4= uptake measurement. With this aim, erythrocytes were exposed to a mild and transient oxidative stress (30 min to either 10 or 100 μM H2O2), followed by a stronger oxidant condition (300- or, alternatively, 600-μM H2O2 treatment). SO4= uptake was measured by a turbidimetric method, and the possible role of catalase (CAT, significantly contributing to the anti-oxidant system in erythrocytes) in PC response has been verified by measuring the rate of H2O2 degradation. The preventive exposure of erythrocytes to 10 μM H2O2, and then to 300 μM H2O2, significantly ameliorated the rate constant for SO4= uptake with respect to 300 μM H2O2 alone, showing thus an adaptive response to oxidative stress. Our results show that (i) SO4= uptake measurement is a suitable model to monitor the effects of a mild and transient oxidative stress in human erythrocytes, (ii) band 3 protein anion exchange capability is retained after 10 μM H2O2 treatment, (iii) PC response induced by the 10 μM H2O2 pretreatment is clearly detected, and (iv) PC response, elicited by low-concentrated H2O2, is mediated by CAT enzyme and does not involve band 3 protein tyrosine phosphorylation pathways. Erythrocyte adaptation to a short-term oxidative stress may serve as a basis for future studies about the impact of more prolonged oxidative events, often associated to aging, drug consumption, chronic alcoholism, hyperglycemia, or neurodegenerative diseases.

  11. Stimulation of Suicidal Erythrocyte Death by Increased Extracellular Phosphate Concentrations

    Directory of Open Access Journals (Sweden)

    Jakob Voelkl

    2014-02-01

    Full Text Available Background/Aim: Anemia in renal insufficiency results in part from impaired erythrocyte formation due to erythropoietin and iron deficiency. Beyond that, renal insufficiency enhances eryptosis, the suicidal erythrocyte death characterized by phosphatidylserine-exposure at the erythrocyte surface. Eryptosis may be stimulated by increase of cytosolic Ca2+-activity ([Ca2+]i. Several uremic toxins have previously been shown to stimulate eryptosis. Renal insufficiency is further paralleled by increase of plasma phosphate concentration. The present study thus explored the effect of phosphate on erythrocyte death. Methods: Cell volume was estimated from forward scatter, phosphatidylserine-exposure from annexin V binding, and [Ca2+]i from Fluo3-fluorescence. Results: Following a 48 hours incubation, the percentage of phosphatidylserine exposing erythrocytes markedly increased as a function of extracellular phosphate concentration (from 0-5 mM. The exposure to 2 mM or 5 mM phosphate was followed by slight but significant hemolysis. [Ca2+]i did not change significantly up to 2 mM phosphate but significantly decreased at 5 mM phosphate. The effect of 2 mM phosphate on phosphatidylserine exposure was significantly augmented by increase of extracellular Ca2+ to 1.7 mM, and significantly blunted by nominal absence of extracellular Ca2+, by additional presence of pyrophosphate as well as by presence of p38 inhibitor SB203580. Conclusion: Increasing phosphate concentration stimulates erythrocyte membrane scrambling, an effect depending on extracellular but not intracellular Ca2+ concentration. It is hypothesized that suicidal erythrocyte death is triggered by complexed CaHPO4.

  12. Erythrocyte G protein as a novel target for malarial chemotherapy.

    Directory of Open Access Journals (Sweden)

    Sean C Murphy

    2006-12-01

    Full Text Available Malaria remains a serious health problem because resistance develops to all currently used drugs when their parasite targets mutate. Novel antimalarial drug targets are urgently needed to reduce global morbidity and mortality. Our prior results suggested that inhibiting erythrocyte Gs signaling blocked invasion by the human malaria parasite Plasmodium falciparum.We investigated the erythrocyte guanine nucleotide regulatory protein Gs as a novel antimalarial target. Erythrocyte "ghosts" loaded with a Gs peptide designed to block Gs interaction with its receptors, were blocked in beta-adrenergic agonist-induced signaling. This finding directly demonstrates that erythrocyte Gs is functional and that propranolol, an antagonist of G protein-coupled beta-adrenergic receptors, dampens Gs activity in erythrocytes. We subsequently used the ghost system to directly link inhibition of host Gs to parasite entry. In addition, we discovered that ghosts loaded with the peptide were inhibited in intracellular parasite maturation. Propranolol also inhibited blood-stage parasite growth, as did other beta2-antagonists. beta-blocker growth inhibition appeared to be due to delay in the terminal schizont stage. When used in combination with existing antimalarials in cell culture, propranolol reduced the 50% and 90% inhibitory concentrations for existing drugs against P. falciparum by 5- to 10-fold and was also effective in reducing drug dose in animal models of infection.Together these data establish that, in addition to invasion, erythrocyte G protein signaling is needed for intracellular parasite proliferation and thus may present a novel antimalarial target. The results provide proof of the concept that erythrocyte Gs antagonism offers a novel strategy to fight infection and that it has potential to be used to develop combination therapies with existing antimalarials.

  13. [The condition of the oxidant-antioxidant system of plasma and of blood erythrocytes in patients with severe renal insufficiency, anuria stage, due to compression trauma].

    Science.gov (United States)

    Tarakanov, A V; Klimov, L V; Usalev, N N

    2004-01-01

    The lipid peroxidation processes as well as the activity of the antioxidant system of plasma and of blood erythrocytes were analyzed in severe renal insufficiency due to acute compression trauma. The levels of diene conjugates, malonic dialdehyde and shiff bases were found to be reliably higher in plasma in the anuria stage; as for erythrocytes, only the level of the final peroxidation products, i.e. shiff bases, turned out to be higher in their case. The antioxidant system reaction was as follows: a reliable decrease of the ceruplasmin level was registered in blood plasma, and a reduced activity of superoxide dismutase was detected in erythrocytes. No changed catalase activity was registered either in plasma or erythrocytes versus the controls. The occurred lipid-peroxidation activation had, in the erythrocyte membranes, a negative effect on the protein-lipid contact zones. According to the obtained results, it is necessary to use antioxidants and activation of the non-enzyme system within the complex therapy for the purpose of preventing the secondary damage to cellular membranes.

  14. Effect of erythrocyte heat treatment on pulmonary vascular resistance.

    Science.gov (United States)

    Hakim, T S

    1994-07-01

    The effect of red blood cell deformability on the pulmonary vascular resistance was studied in isolated dog and rat lungs. Blood cells were incubated at 49 degrees C for 1 hr, to render them rigid. The resistance to blood flow in the lung was assessed either by calculating the pulmonary vascular resistance (PVR = arterial - venous pressure difference divided by flow rate) or by examining the vascular pressure-flow relationship for changes in slope and intercept. The resistance in the lung was first assessed during perfusion with normal blood and again during perfusion with rigid cells. The results showed that PVR in dog lungs increased by 15% during perfusion with heat-treated blood and that this increase in PVR was associated with a significant increase in the middle segment resistance (arterial-venous occlusion technique) and with an increase in critical closing pressure (pressure intercept of the pressure-flow curve). In contrast to the small effect in dog lungs, the PVR in rat lungs rose more than 400% during perfusion with heat-treated blood. The marked increase of PVR in rat lungs was prevented with papaverine (PVR increased only 58%), suggesting that vasoconstriction was a primary event in rat lungs. The rise in vascular resistance in rat lungs was further shown to be primarily due to the presence of rigid erythrocytes (RBC). The increase in PVR in the rat lungs was not due to mechanical obstruction of the vasculature but rather to constriction of arteries and veins (double occlusion technique). The conclusion from this study is that RBC deformability plays an important role in the pulmonary vasculature, primarily because of release of vasoactive substances and partially because of the potential mechanical obstruction of capillaries. These events are apparently species dependent and are attributed mostly to red blood cell deformability which decreases during heat treatment.

  15. Erythrocyte-bound apolipoprotein B in atherosclerosis and mortality.

    Science.gov (United States)

    de Vries, Marijke A; van Santen, Selvetta S; Klop, Boudewijn; van der Meulen, Noëlle; van Vliet, Marjolein; van de Geijn, Gert-Jan M; van der Zwan-van Beek, Ellen M; Birnie, Erwin; Liem, Anho H; de Herder, Wouter W; Castro Cabezas, Manuel

    2017-04-01

    The binding of apolipoprotein (apo) B-containing lipoproteins to circulating erythrocytes (ery-apoB) is associated with a decreased prevalence of atherosclerosis. In this study, we evaluated ery-apoB as a possible prognostic factor in cardiovascular events and all-cause mortality, in a prospective cohort study. Ery-apoB was measured by flow cytometry in subjects with and without cardiovascular disease (CVD). The primary endpoint was the cardiovascular event rate. Secondary endpoints were all-cause mortality and the combined endpoint of all-cause mortality and cardiovascular events (any event rate). A Cox regression analysis with univariate and multivariate analyses and Kaplan-Meier survival analysis was performed. Follow-up data were available of 384 subjects. Subjects were divided according to high (> 2·0 au, n = 60), intermediate (0·2-2·0 au, n = 274) or low (mortality [HR 9·9 (1·2-79·0), P = 0·031] and any event rate [HR 3·4 (95% CI 1·3-8·7), P = 0·012]. In a Cox regression analysis, only a history of CVD was significantly associated with any event rate [HR 3·6 (1·6-8·0), P = 0·002], while low ery-apoB showed a trend [HR 2·4 (0·9-6·4), P = 0·07]. In a subgroup analysis, in subjects with a history of CVD, ery-apoB was significantly associated with all-cause mortality (log rank P = 0·021) and any event rate (log rank P = 0·009). Low ery-apoB is associated with increased mortality and cardiovascular risk, especially in patients with a prior history of CVD. These subjects may benefit from more aggressive secondary prevention treatment. © 2017 Stichting European Society for Clinical Investigation Journal Foundation.

  16. Biophysics of malarial parasite exit from infected erythrocytes.

    Science.gov (United States)

    Chandramohanadas, Rajesh; Park, YongKeun; Lui, Lena; Li, Ang; Quinn, David; Liew, Kingsley; Diez-Silva, Monica; Sung, Yongjin; Dao, Ming; Lim, Chwee Teck; Preiser, Peter Rainer; Suresh, Subra

    2011-01-01

    Upon infection and development within human erythrocytes, P. falciparum induces alterations to the infected RBC morphology and bio-mechanical properties to eventually rupture the host cells through parasitic and host derived proteases of cysteine and serine families. We used previously reported broad-spectrum inhibitors (E64d, EGTA-AM and chymostatin) to inhibit these proteases and impede rupture to analyze mechanical signatures associated with parasite escape. Treatment of late-stage iRBCs with E64d and EGTA-AM prevented rupture, resulted in no major RBC cytoskeletal reconfiguration but altered schizont morphology followed by dramatic re-distribution of three-dimensional refractive index (3D-RI) within the iRBC. These phenotypes demonstrated several-fold increased iRBC membrane flickering. In contrast, chymostatin treatment showed no 3D-RI changes and caused elevated fluctuations solely within the parasitophorous vacuole. We show that E64d and EGTA-AM supported PV breakdown and the resulting elevated fluctuations followed non-Gaussian pattern that resulted from direct merozoite impingement against the iRBC membrane. Optical trapping experiments highlighted reduced deformability of the iRBC membranes upon rupture-arrest, more specifically in the treatments that facilitated PV breakdown. Taken together, our experiments provide novel mechanistic interpretations on the role of parasitophorous vacuole in maintaining the spherical schizont morphology, the impact of PV breakdown on iRBC membrane fluctuations leading to eventual parasite escape and the evolution of membrane stiffness properties of host cells in which merozoites were irreversibly trapped, recourse to protease inhibitors. These findings provide a comprehensive, previously unavailable, body of information on the combined effects of biochemical and biophysical factors on parasite egress from iRBCs.

  17. Mice Deficient in the Putative Phospholipid Flippase ATP11C Exhibit Altered Erythrocyte Shape, Anemia, and Reduced Erythrocyte Life Span*♦

    Science.gov (United States)

    Yabas, Mehmet; Coupland, Lucy A.; Cromer, Deborah; Winterberg, Markus; Teoh, Narci C.; D'Rozario, James; Kirk, Kiaran; Bröer, Stefan; Parish, Christopher R.; Enders, Anselm

    2014-01-01

    Transmembrane lipid transporters are believed to establish and maintain phospholipid asymmetry in biological membranes; however, little is known about the in vivo function of the specific transporters involved. Here, we report that developing erythrocytes from mice lacking the putative phosphatidylserine flippase ATP11C showed a lower rate of PS translocation in vitro compared with erythrocytes from wild-type littermates. Furthermore, the mutant mice had an elevated percentage of phosphatidylserine-exposing mature erythrocytes in the periphery. Although erythrocyte development in ATP11C-deficient mice was normal, the mature erythrocytes had an abnormal shape (stomatocytosis), and the life span of mature erythrocytes was shortened relative to that in control littermates, resulting in anemia in the mutant mice. Thus, our findings uncover an essential role for ATP11C in erythrocyte morphology and survival and provide a new candidate for the rare inherited blood disorder stomatocytosis with uncompensated anemia. PMID:24898253

  18. Detection of Occult Erythrocytic Membrane Damages upon Pharmacological Exposures

    Directory of Open Access Journals (Sweden)

    P. Yu. Alekseyeva

    2007-01-01

    Full Text Available Blood administration of pharmaceuticals may cause occult effects of these agents on erythrocytic membranes. These effects may damage and cause additional membrane defects, but may strengthen. The type and degree of the effects of an agent were detected by calibrated irreversible electroporation with a pulsed electric field (PEF. The paper considers the erythrocytic membranous effects of a wide concentration range of agents used in anesthesiology, such as esmerone, tracrium, and mar-caine-adrenaline. Under the action of PEF and esmerone at the normal concentration N, the rate of erythrocytic hemolysis increased by several times as compared with the control. The similar effect also occurred when esmerone was added at the concentration C=10N. Tracrium exerted a fixing effect on erythrocytic membranes. Upon a combined exposure to PEF and tracrium in the normal concentration C=N; erythrocytic hemolysis was slow. So was with the concentration C=10N. The rate of hemolysis of the red blood cells subjected to a combined action of marcaine adrenaline at the normal concentration C=N and even at the concentration C=10N and PEF was comparable with the hemolytic rate of the reference suspension. 

  19. Chloramines and hypochlorous acid oxidize erythrocyte peroxiredoxin 2.

    Science.gov (United States)

    Stacey, Melissa M; Peskin, Alexander V; Vissers, Margreet C; Winterbourn, Christine C

    2009-11-15

    Peroxiredoxin 2 (Prx2) is an abundant thiol protein that is readily oxidized in erythrocytes exposed to hydrogen peroxide. We investigated its reactivity in human erythrocytes with hypochlorous acid (HOCl) and chloramines, relevant oxidants in inflammation. Prx2 was oxidized to a disulfide-linked dimer by HOCl, glycine chloramine (GlyCl), and monochloramine (NH(2)Cl) in a dose-dependent manner. In the absence of added glucose, Prx2 and GSH showed similar sensitivities. Second-order rate constants for the reactions of Prx2 with NH(2)Cl and GlyCl were 1.5 x 10(4) and 8 M(-1) s(-1), respectively. The NH(2)Cl value is approximately 10 times higher than that for GSH, whereas Prx2 is approximately 30 times less sensitive than GSH to GlyCl. Thus, the relative sensitivity of Prx2 to GlyCl is greater in the erythrocyte. Oxidation of erythrocyte Prx2 and GSH was less in the presence of glucose, probably because of recycling. High doses of NH(2)Cl resulted in incomplete regeneration of reduced Prx2, suggesting impairment of the recycling mechanism. Our results show that, although HOCl and chloramines are less selective than H(2)O(2), they nevertheless oxidize Prx2. Exposure to these inflammatory oxidants will result in Prx2 oxidation and could compromise the erythrocyte's ability to resist damaging oxidative insult.

  20. Stimulation of erythrocyte cell membrane scrambling by amiodarone.

    Science.gov (United States)

    Nicolay, Jan P; Bentzen, Peter J; Ghashghaeinia, Mehrdad; Wieder, Thomas; Lang, Florian

    2007-01-01

    Side effects of amiodarone, an effective antiarrhythmic drug, include anemia, which may be caused by decreased formation or accelerated death of erythrocytes. Suicidal erythrocyte death (eryptosis) is characterized by cell shrinkage and cell membrane scrambling leading to phosphatidylserine exposure at the cell surface. Stimulators of erythrocyte membrane scrambling include increase of cytosolic Ca2+ concentration ([Ca2+]i) following activation of Ca2+-permeable cation channels. Moreover, eryptosis is triggered by ceramide. The present study has been performed to test for an effect of amiodarone on eryptosis. Erythrocytes from healthy volunteers were exposed to amiodarone and phosphatidylserine exposure (annexin V binding), cell volume (forward scatter), [Ca2+]i (Fluo3-dependent fluorescence), and ceramide formation (anti-ceramide-FITC antibody and radioactive labelling) determined by flow cytometry. Exposure of erythrocytes to amiodarone (1 microM) increased [Ca2+]i and triggered annexin V binding, but did not significantly decrease forward scatter and did not significantly influence ceramide formation. Amiodarone augmented the increase of annexin binding following hypertonic shock (addition of 550 mM sucrose) but did not significantly alter the enhanced annexin binding following Cl- removal (replacement with gluconate). Amiodarone did not significantly modify the decrease of forward scatter following hypertonic shock or Cl- removal. The present observations disclose a novel action of amiodarone which may contribute to the side effects of the drug.

  1. Very Deep Convolutional Neural Networks for Morphologic Classification of Erythrocytes.

    Science.gov (United States)

    Durant, Thomas J S; Olson, Eben M; Schulz, Wade L; Torres, Richard

    2017-12-01

    Morphologic profiling of the erythrocyte population is a widely used and clinically valuable diagnostic modality, but one that relies on a slow manual process associated with significant labor cost and limited reproducibility. Automated profiling of erythrocytes from digital images by capable machine learning approaches would augment the throughput and value of morphologic analysis. To this end, we sought to evaluate the performance of leading implementation strategies for convolutional neural networks (CNNs) when applied to classification of erythrocytes based on morphology. Erythrocytes were manually classified into 1 of 10 classes using a custom-developed Web application. Using recent literature to guide architectural considerations for neural network design, we implemented a "very deep" CNN, consisting of >150 layers, with dense shortcut connections. The final database comprised 3737 labeled cells. Ensemble model predictions on unseen data demonstrated a harmonic mean of recall and precision metrics of 92.70% and 89.39%, respectively. Of the 748 cells in the test set, 23 misclassification errors were made, with a correct classification frequency of 90.60%, represented as a harmonic mean across the 10 morphologic classes. These findings indicate that erythrocyte morphology profiles could be measured with a high degree of accuracy with "very deep" CNNs. Further, these data support future efforts to expand classes and optimize practical performance in a clinical environment as a prelude to full implementation as a clinical tool. © 2017 American Association for Clinical Chemistry.

  2. A nature-inspired betalainic probe for live-cell imaging of Plasmodium-infected erythrocytes.

    Directory of Open Access Journals (Sweden)

    Letícia Christina Pires Gonçalves

    Full Text Available A model betalainic dye was semisynthesized from betanin, the magenta pigment of the red beet, and was effective for live-cell imaging of Plasmodium-infected red blood cells. This water-soluble fluorescent probe is photostable, excitable in the visible region and cell membrane-permeable, and its photophysical properties are not notably pH-sensitive. Fluorescence imaging microscopy of erythrocytes infected with Plasmodium falciparum, a causative agent of malaria in humans, showed that only the parasite was stained. Z-stacking analysis suggested that the probe accumulates proximal to the nucleus of the parasite. Indicaxanthin, one of the natural fluorescent betalains found in the petals of certain flowers, did not stain the parasite or the red blood cell.

  3. Detection of antibodies to variant antigens on Plasmodium falciparum-infected erythrocytes by flow cytometry

    DEFF Research Database (Denmark)

    Staalsoe, T; Giha, H A; Dodoo, D

    1999-01-01

    BACKGROUND: Naturally induced antibodies binding to surface antigens of Plasmodium falciparum-infected erythrocytes can be detected by direct agglutination of infected erythrocytes or by indirect immunofluorescence on intact, unfixed, infected erythrocytes. Agglutinating antibodies have previously...

  4. Supernatant of Aged Erythrocytes Causes Lung Inflammation and Coagulopathy in a "Two-Hit" In Vivo Syngeneic Transfusion Model

    NARCIS (Netherlands)

    Vlaar, Alexander P. J.; Hofstra, Jorrit J.; Levi, Marcel; Kulik, Willem; Nieuwland, Rienk; Tool, Anton T. J.; Schultz, Marcus J.; de Korte, Dirk; Juffermans, Nicole P.

    2010-01-01

    Background: Transfusion of erythrocytes is associated with increased morbidity in certain patient groups. Storage time of erythrocytes may contribute to respiratory complications. Using a syngeneic in vivo transfusion model, we investigated whether transfusion of stored rat erythrocytes causes lung

  5. An expanding toolkit for preclinical pre-erythrocytic malaria vaccine development: bridging traditional mouse malaria models and human trials.

    Science.gov (United States)

    Steel, Ryan Wj; Kappe, Stefan Hi; Sack, Brandon K

    2016-12-01

    Malaria remains a significant public health burden with 214 million new infections and over 400,000 deaths in 2015. Elucidating relevant Plasmodium parasite biology can lead to the identification of novel ways to control and ultimately eliminate the parasite within geographic areas. Particularly, the development of an effective vaccine that targets the clinically silent pre-erythrocytic stages of infection would significantly augment existing malaria elimination tools by preventing both the onset of blood-stage infection/disease as well as spread of the parasite through mosquito transmission. In this Perspective, we discuss the role of small animal models in pre-erythrocytic stage vaccine development, highlighting how human liver-chimeric and human immune system mice are emerging as valuable components of these efforts.

  6. Programmed co-delivery of paclitaxel and doxorubicin boosted by camouflaging with erythrocyte membrane

    Science.gov (United States)

    Fu, Qiang; Lv, Piping; Chen, Zhongke; Ni, Dezhi; Zhang, Lijun; Yue, Hua; Yue, Zhanguo; Wei, Wei; Ma, Guanghui

    2015-02-01

    Combination chemotherapy has been proven promising for cancer treatment, but unsatisfactory therapeutic data and increased side effects slow down the development in the clinic. In this study, we develop an effective approach to co-encapsulate a hydrophilic-hydrophobic chemotherapeutic drug pair (paclitaxel and doxorubicin) into magnetic O-carboxymethyl-chitosan nanoparticles. To endow them with the ability of programmed delivery, these carriers are further camouflaged with an Arg-Gly-Asp anchored erythrocyte membrane. Compared with the traditional polyethylene glycol coating method, this biomimetic decoration strategy is demonstrated to be superior in prolonging circulation time, improving tumor accumulation, facilitating tumor uptake, and tuning intracellular fate. These outstanding properties enable the as-designed nanodevice to exhibit greater tumor growth inhibition ability and much lower side effects than the combined use of commercial formulations.Combination chemotherapy has been proven promising for cancer treatment, but unsatisfactory therapeutic data and increased side effects slow down the development in the clinic. In this study, we develop an effective approach to co-encapsulate a hydrophilic-hydrophobic chemotherapeutic drug pair (paclitaxel and doxorubicin) into magnetic O-carboxymethyl-chitosan nanoparticles. To endow them with the ability of programmed delivery, these carriers are further camouflaged with an Arg-Gly-Asp anchored erythrocyte membrane. Compared with the traditional polyethylene glycol coating method, this biomimetic decoration strategy is demonstrated to be superior in prolonging circulation time, improving tumor accumulation, facilitating tumor uptake, and tuning intracellular fate. These outstanding properties enable the as-designed nanodevice to exhibit greater tumor growth inhibition ability and much lower side effects than the combined use of commercial formulations. Electronic supplementary information (ESI) available. See DOI

  7. Fetal-maternal erythrocyte distribution blood test

    Science.gov (United States)

    ... helps find out how much Rh immune globulin (RhoGAM) she must receive to prevent her body from ... in the mother's blood. The standard dose of RhoGAM is enough in this case. Normal value ranges ...

  8. A novel approach for assessments of erythrocyte sedimentation rate.

    Science.gov (United States)

    Pribush, A; Hatskelzon, L; Meyerstein, N

    2011-06-01

    Previous studies have shown that the dispersed phase of sedimenting blood undergoes dramatic structural changes: Discrete red blood cell (RBC) aggregates formed shortly after a settling tube is filled with blood are combined into a continuous network followed by its collapse via the formation of plasma channels, and finally, the collapsed network is dispersed into individual fragments. Based on this scheme of structural transformation, a novel approach for assessments of erythrocyte sedimentation is suggested. Information about erythrocyte sedimentation is extracted from time records of the blood conductivity measured after a dispersion of RBC network into individual fragments. It was found that the sedimentation velocity of RBC network fragments correlates positively with the intensity of attractive intercellular interactions, whereas no effect of hematocrit (Hct) was observed. Thus, unlike Westergren erythrocyte sedimentation rate, sedimentation data obtained by the proposed method do not require correction for Hct. © 2010 Blackwell Publishing Ltd.

  9. Genotoxic Biomarkers in Erythrocytes of Lepidochelys olivacea (Cheloniidae from Colombia

    Directory of Open Access Journals (Sweden)

    Victor Hugo Quiroz Herrera

    2017-09-01

    Full Text Available This research was conducted in the municipality of Bahia Solano, Colombia, and had as a goal to detect damage erythrocytes circulating with nuclear lesions in fifty-five Olive Ridley adult females using acridine orange immunostain, and correlate its frequencies with some physiological and biometric parameters. We determine a micronucleated erythrocytes (MNE frequency of 0.6 ± 0.6 and nuclear buds (NBE of 2.1 ± 1.9. We not found any relationship between the nuclear lesions with physiological or biometric parameters evaluated (Pearson and Kruskal-Wallis, p<0.05. We define a significative statistical difference (p=0.035 between both nuclear lesions frequencies. This results show nuclear damages in erythrocytes of Olive Ridley sea turtle for the first time in Colombia as an outcome of genotoxic stress. Also contributes key information for future research in the ecotoxicology area for endangered marine species.

  10. Simulation of dielectric spectra of erythrocytes with various shapes

    Energy Technology Data Exchange (ETDEWEB)

    Asami, Koji, E-mail: asami@e.kuicr.kyoto-u.ac.j [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan)

    2009-07-07

    Dielectric spectra of erythrocyte suspensions were numerically simulated over a frequency range from 1 kHz to 100 MHz to study the effects of erythrocyte shape on the dielectric spectra. First, a biconcave-discoid model for normal erythrocytes or discocytes was compared with an equivalent oblate spheroid model. The two models showed similar dielectric spectra to each other, suggesting that the oblate spheroid model can be approximately used for discocytes. Second, dielectric spectra were simulated for discocytes deformed by osmotic cell swelling. The deformation resulted in the increase in relaxation intensity and the sharpening of spectrum shape. Finally, dielectric spectra were simulated for echinocytes, stomatocytes and sickle cells that are induced by chemical agents and diseases. The dielectric spectra of echinocytes and stomatocytes were similar to each other, being distinguishable from that of discocytes and quite different from that of sickle cells.

  11. Segmentation of leukocytes and erythrocytes in blood smear images.

    Science.gov (United States)

    Bergen, Tobias; Steckhan, Dirk; Wittenberg, Thomas; Zerfass, Thorsten

    2008-01-01

    Differential blood count is a standard method in hematological laboratory diagnosis. In the course of developing a computer-assisted microscopy system for the generation of differential blood counts, the detection and segmentation of white and red blood cells forms an essential step and its exactness is a fundamental prerequisite for the effectiveness of the subsequent classification step. We propose a method for the exact segmentation of leukocytes and erythrocytes in a simultaneous and cooperative way. We combine pixel-wise classification with template matching to locate erythrocytes and use a level-set approach in order to get the exact cell contours of leukocyte nucleus and plasma regions as well as erythrocyte regions. An evaluation comparing the performance of the algorithm to the manual segmentation performed by several persons yielded good results.

  12. Identification of Novel Membrane Structures in Plasmodium falciparum Infected Erythrocytes

    Directory of Open Access Journals (Sweden)

    Clavijo Carlos A

    1998-01-01

    Full Text Available Little is known about the molecular mechanisms underlying the release of merozoites from malaria infected erythrocytes. In this study membranous structures present in the culture medium at the time of merozoite release have been characterized. Biochemical and ultrastructural evidence indicate that membranous structures consist of the infected erythrocyte membrane, the parasitophorous vacuolar membrane and a residual body containing electron dense material. These are subcellular compartments expected in a structure that arises as a consequence of merozoite release from the infected cell. Ultrastructural studies show that a novel structure extends from the former parasite compartment to the surface membrane. Since these membrane modifications are detected only after merozoites have been released from the infected erythrocyte, it is proposed that they might play a role in the release of merozoites from the host cell

  13. Formulation and Drug Loading Features of Nano-Erythrocytes

    Science.gov (United States)

    Dong, Xiaoting; Niu, Yawei; Ding, Yi; Wang, Yuemin; Zhao, Jialan; Leng, Wei; Qin, Linghao

    2017-03-01

    Nano erythrocyte ghosts have recently been used as drug carriers of water-soluble APIs due to inherit biological characteristics of good compatibility, low toxicity, and small side-effect. In this study, we developed a novel drug delivery system based on nano erythrocyte ghosts (STS-Nano-RBCs) to transport Sodium Tanshinone IIA sulfonate (STS) for intravenous use in rat. STS-Nano-RBCs were prepared by hypotonic lysis and by extrusion methods, and its biological properties were investigated compared with STS injection. The results revealed that STS-Nano-RBCs have narrow particle size distribution, good drug loading efficiency, and good stability within 21 days. Compared with STS injection, STS-Nano-RBCs extended the drug release time in vitro and in vivo with better repairing effect on oxidative stress-impaired endothelial cells. These results suggest that the nano erythrocyte ghosts system could be used to deliver STS.

  14. The interactions of fibrinogen and dextrans with erythrocytes

    Science.gov (United States)

    Rampling, M.; Sirs, John A.

    1972-01-01

    1. The rate of packing of erythrocytes in whole blood, under a centrifugal field of 200 g, has been studied using an automatic recording centrifuge. 2. Reduction of the supernatant fibrinogen concentration, by repeatedly washing the cells, lowers the rate of packing and reduces the cell flexibility. 3. Resuspending the cells in their own plasma or in isotonic solutions containing fibrinogen restores their flexibility. 4. Rouleaux formation has been shown to have no effect on the rate of packing by comparison of blood diluted with plasma, isotonic NaCl or Ringer—Locke solutions. While the degree of rouleaux formation varied with the diluent used, the rate of packing and packed cell haematocrit were the same, for the same dilution. 5. Both formalin and dextran altered the degree of rouleaux formation and reduced erythrocyte flexibility. Dextran was found to act indirectly on the erythrocyte flexibility by reducing the plasma fibrinogen concentration. PMID:5046146

  15. Inhibition of Suicidal Erythrocyte Death by Indirubin-3'-Monoxime.

    Science.gov (United States)

    Liu, Chunqiu; Jiang, Peipei; Xu, Yuanhong; Zheng, Meijuan; Qiao, Jinpin; Zhou, Xueyong; Huang, Dake; Bian, Maohong

    2018-01-01

    Qing Dai is a prized traditional Chinese medicine whose major component, indirubin, and its derivative, indirubin-3'-monoxime (IDM), have inhibitory effects on the growth of many human tumor cells and pronounced anti-leukemic activities. However, the effects of IDM on mature human erythrocytes are unclear. This study aimed to evaluate the potential impact of IDM on erythrocytes and the mechanisms underlying that impact. Utilizing flow cytometry and confocal laser scanning microscopy, phosphatidylserine exposure at the cell surface was estimated by annexin V-fluorescein isothiocyanate (FITC). The relative cell size, expressed in arbitrary units, was evaluated by forward scatter in a flow cytometer. Fluo-3 fluorescence was used to bewrite changes in cytosolic Ca2+ activity, reactive oxygen species (ROS) formation was assessed by 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescence, and ceramide abundance was evaluated by FITC-conjugated specific antibodies. The 24-h exposure of human erythrocytes to IDM (12 µM) significantly decreased the percentage of annexin V-binding erythrocytes and the intracellular calcium concentration ([Ca2+]i). IDM (3-12 µM) did not significantly modify the ceramide level or DCFH-DA fluorescence. Energy depletion (removal of glucose for 24 hours) significantly increased annexin V binding and Fluo-3 fluorescence and diminished forward scatter, and these effects were significantly mitigated by IDM (12 µM). Moreover, the Ca2+ ionophore ionomycin (1 µM, 60 min) and oxidative stress (30 min exposure to 0.05 mM tert-butyl hydroperoxide, t-BHP) similarly triggered eryptosis, which was also significantly suppressed by IDM. IDM is a novel inhibitor of suicidal erythrocyte death following ionomycin treatment, t-BHP treatment and energy depletion. Thus, IDM may counteract anemia and impairment of microcirculation, at least in part, by inhibition of Ca2+ entry into erythrocytes. © 2018 The Author(s). Published by S. Karger AG, Basel.

  16. Stimulating Effect of Elvitegravir on Suicidal Erythrocyte Death

    Directory of Open Access Journals (Sweden)

    Rosi Bissinger

    2016-03-01

    Full Text Available Background/Aims: The antiviral drug Elvitegravir is used for the treatment of Human Immunodeficiency Virus (HIV infections. The present study explored whether the drug is able to trigger eryptosis, the suicidal death of erythrocytes. Eryptosis is characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Stimulators of eryptosis include increase of cytosolic Ca2+ activity ([Ca2+]i, oxidative stress, ceramide, activated p38 kinase and activated caspases. The present study explored, whether Elvitegravir induces eryptosis and, if so, to shed light on the mechanisms involved. Methods: Phosphatidylserine abundance at the erythrocyte surface was estimated from annexin-V-binding, cell volume from forward scatter, [Ca2+]i from Fluo3-fluorescence, abundance of reactive oxygen species (ROS from DCFDA dependent fluorescence, and ceramide abundance at the erythrocyte surface utilizing specific antibodies. Results: A 48 hours exposure of human erythrocytes to Elvitegravir (≥ 1.5 µg/ml significantly increased the percentage of annexin-V-binding cells, and significantly decreased forward scatter. Elvitegravir (2.5 µg/ml significantly increased Fluo3-fluorescence, but did not significantly modify DCFDA fluorescence or ceramide abundance. The effect of Elvitegravir on annexin-V-binding was significantly blunted by removal of extracellular Ca2+, but not in the presence of p38 kinase inhibitor SB203580 (2 µM or in the presence of pancaspase inhibitor zVAD (10 µM. Conclusions: Elvitegravir triggers cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect in part due to entry of extracellular Ca2+.

  17. Erythrocyte Stiffness during Morphological Remodeling Induced by Carbon Ion Radiation

    Science.gov (United States)

    Zhang, Baoping; Liu, Bin; Zhang, Hong; Wang, Jizeng

    2014-01-01

    The adverse effect induced by carbon ion radiation (CIR) is still an unavoidable hazard to the treatment object. Thus, evaluation of its adverse effects on the body is a critical problem with respect to radiation therapy. We aimed to investigate the change between the configuration and mechanical properties of erythrocytes induced by radiation and found differences in both the configuration and the mechanical properties with involving in morphological remodeling process. Syrian hamsters were subjected to whole-body irradiation with carbon ion beams (1, 2, 4, and 6 Gy) or X-rays (2, 4, 6, and 12 Gy) for 3, 14 and 28 days. Erythrocytes in peripheral blood and bone marrow were collected for cytomorphological analysis. The mechanical properties of the erythrocytes were determined using atomic force microscopy, and the expression of the cytoskeletal protein spectrin-α1 was analyzed via western blotting. The results showed that dynamic changes were evident in erythrocytes exposed to different doses of carbon ion beams compared with X-rays and the control (0 Gy). The magnitude of impairment of the cell number and cellular morphology manifested the subtle variation according to the irradiation dose. In particular, the differences in the size, shape and mechanical properties of the erythrocytes were well exhibited. Furthermore, immunoblot data showed that the expression of the cytoskeletal protein spectrin-α1 was changed after irradiation, and there was a common pattern among its substantive characteristics in the irradiated group. Based on these findings, the present study concluded that CIR could induce a change in mechanical properties during morphological remodeling of erythrocytes. According to the unique characteristics of the biomechanical categories, we deduce that changes in cytomorphology and mechanical properties can be measured to evaluate the adverse effects generated by tumor radiotherapy. Additionally, for the first time, the current study provides a new

  18. Viral erythrocytic necrosis: Chapter 2.2.7

    Science.gov (United States)

    Winton, James R.; Hershberger, Paul K.

    2014-01-01

    Viral erythrocytic necrosis (VEN), originally termed piscine erythrocytic necrosis, is a condition that has been reported to affect the red blood cells (RBCs) of many species of marine and anadromous fishes in both the Atlantic and Pacific Oceans (Nicholson and Reno 1981; Smail 1982; Wolf 1988; Dannevig and Thorud 1999). Fish with VEN may develop a severe anemia that can reduce their stamina, predispose them to other infections or increase the impact of other stressors (MacMillan et al. 1980; Nicholson and Reno 1981; Meyers et al. 1986; Haney et al. 1992) resulting in population-scale impacts in susceptible species (Hershberger et al. 2009).

  19. Electrophysiological studies of malaria parasite-infected erythrocytes: Current status

    Science.gov (United States)

    Staines, Henry M.; Alkhalil, Abdulnaser; Allen, Richard J.; De Jonge, Hugo R.; Derbyshire, Elvira; Egée, Stéphane; Ginsburg, Hagai; Hill, David A.; Huber, Stephan M.; Kirk, Kiaran; Lang, Florian; Lisk, Godfrey; Oteng, Eugene; Pillai, Ajay D.; Rayavara, Kempaiah; Rouhani, Sherin; Saliba, Kevin J.; Shen, Crystal; Solomon, Tsione; Thomas, Serge L. Y.; Verloo, Patrick; Desai, Sanjay A.

    2009-01-01

    The altered permeability characteristics of erythrocytes infected with malaria parasites have been a source of interest for over 30 years. Recent electrophysiological studies have provided strong evidence that these changes reflect transmembrane transport through ion channels in the host erythrocyte plasma membrane. However, conflicting results and differing interpretations of the data have led to confusion in this field. In an effort to unravel these issues, the groups involved recently came together for a week of discussion and experimentation. In this article, the various models for altered transport are reviewed, together with the areas of consensus in the field and those that require a better understanding. PMID:17292372

  20. [Relevance of erythrocyte parameters on fluid management in critical care].

    Science.gov (United States)

    Wang, Zhi-gang; Zhang, Yan; Zhu, Li-hong

    2013-05-01

    To manage fluid therapy in severely ill patients through investigating the relationship between erythrocyte parameters and central venous pressure (CVP) and its denoted blood volume. The research project was divided into two parts. Part I: CVP and concurrent erythrocyte parameters [red blood count (RBC), hemoglobin (Hb), haematocrit (HCT)] were serially recorded in a severely ill patient every morning for 38 days. The obtained values of CVP were divided into three groups (10 cm H2O group), then erythrocyte parameters of each period were compared to obtain the relationship among them. At the same time, "the best" CVP (blood volume was in suitable state) and "the best" erythrocyte parameters (accordingly the blood was not be diluted or concentrated) were obtained. Part II: "the best" CVP and corresponding "the best" erythrocyte parameters were determined in another patient. When the patient's blood volume was in doubt, detected her erythrocyte parameters right away. If the variance between the "practical" and "the best" values was notable, blood volume replenishment or diureses were performed. Then the resulting CVP of fluid expansion or diuresis before and after the treatment were compared, or else other influencing factors should be seeked. Part I: the values of RBC, Hb and HCT in group CVP>10 cm H2O were lower than those of group CVPerythrocyte parameters were determined (RBC was 3.43×10(9)/L, Hb was 97.4 g/L, HCT was 0.310). Part II: "the best" CVP of the this patient was 8 to 10 cm H2O too, accordingly "the best" erythrocyte parameter in term of Hb was 105 g/L. The CVP was obviously elevated in the group in which Hb was higher than "the best" Hb subsequent to fluid expansion (8.29±1.80 cm H2O vs. 5.86±1.57 cm H2O, Perythrocyte parameters, "the best" erythrocyte parameters accompanying "the best" CVP would probably guide fluid therapy best in severely ill patients.

  1. Multiple loci influence erythrocyte phenotypes in the CHARGE Consortium

    OpenAIRE

    Ganesh, Santhi K.; Zakai, Neil A.; van Rooij, Frank J A.; Soranzo, Nicole; Smith, Albert V.; Nalls, Michael A.; Chen, Ming-Huei; Kottgen, Anna; Glazer, Nicole L.; Dehghan, Abbas; Kuhnel, Brigitte; Aspelund, Thor; Yang, Qiong; Tanaka, Toshiko; Jaffe, Andrew

    2009-01-01

    Erythrocyte measures are heritable and have important health implications, yet their genetic determinants are largely unknown. We performed genome-wide association analyses in 24,167 European-ancestry individuals for six erythrocyte traits and identified associations at 23 loci (P values 5?10-8 to 1?10-57). Replication testing in an independent set of 9,456 European-ancestry individuals showed strong evidence of association in all 23 loci in meta-analysis of the discovery and replication coho...

  2. Erythrocyte-derived optical nano-vesicles as theranostic agents

    Science.gov (United States)

    Mac, Jenny T.; Nunez, Vicente; Bahmani, Baharak; Guerrero, Yadir; Tang, Jack; Vullev, Valentine I.; Anvari, Bahman

    2015-07-01

    We have engineered nano-vesicles, derived from erythrocytes, which can be doped with various near infrared (NIR) organic chromophores, including the FDA-approved indocyanine green (ICG). We refer to these vesicles as NIR erythrocyte-mimicking transducers (NETS) since in response to NIR photo-excitation they can generate heat or emit fluorescent light. Using biochemical methods based on reduction amination, we have functionalized the surface of NET with antibodies to target specific biomolecules. We present results that demonstrate the effectiveness of NETs in targeted imaging of cancer cells that over-express the human epidermal growth factor receptor-2 (HER2).

  3. [Effect of PD98059 on Proliferation and Apoptosis of CD71(+),CD235a(+) Nucleated Erythrocytes in the Patients with High Altitude Polycythemia].

    Science.gov (United States)

    Feng, Ting-Ting; Ji, Lin-Hua; Liu, Fang; Han, Yuan-Fang; Ren, Rong; Li, Jian-Ping; Luo, Wei; Su, Juan; Cui, Sen

    2016-08-01

    Objective: To study the effect of PD98059, a specific inhibitor of Ras/Raf/MEK/ERK signaling pathway, on the proliferation and apoptisis of bone marrow CD71(+), CD235a(+) nucleated erythrocytes in patients with high altitude polycythemia (HAPC) and the pathogenesis of HAPC. The CD71(+) and CD235a(+) nucleated erythrocytes in HAPC patients and controls (patients with simple obsolete stracture) were sorted by using the immunemagnetic beads, then were added with 5, 10, 20 µmol/L of PD98059 and DMSO (as control) and were cultured for 72 h under hypoxia. The cell apoptosis was detected by flow cytometry with Annexin V and PI double staining, the cell proliferation was detected by CCK8 method, at same time the erythroid colong-formation ability of bone marrow mononuclear cells (BMMNC) treated with 5, 10, 20 µmol/L of PD98059 and DMSO was observed. With the increase of PD98059 concentration, the apoptosis rate of bone marrow CD71(+) and CD235a(+) nucleated erythrocytes in HAPC patients was enhanced (r=0.807,Perythrocytes in HAPC patients dereased (r=0.502,Perythrocytes in HAPC patients, then inhibit the excessive accumulation of erythrocytes.

  4. Chondroitin sulphate A (CSA)-binding of single recombinant Duffy-binding-like domains is not restricted to Plasmodium falciparum Erythrocyte Membrane Protein 1 expressed by CSA-binding parasites

    DEFF Research Database (Denmark)

    Resende, Mafalda; Ditlev, Sisse B; Nielsen, Morten A

    2009-01-01

    and offspring morbidity, such as severe maternal anaemia and low birth-weight, and is characterised by selective accumulation of parasite-infected erythrocytes (IE) in the placenta. A P. falciparum protein named VAR2CSA, which belongs to the large P. falciparum Erythrocyte Membrane Protein 1 (PfEMP1) family......, enables the IE to bind chondroitin sulphate A (CSA) in the placenta. Knock-out studies have demonstrated the exclusive capacity of VAR2CSA to mediate IE binding to CSA, and it has been shown that four of the six Duffy-binding-like (DBL) domains of VAR2CSA have the ability to bind CSA in vitro...

  5. An in vitro study of adrenaline effect on human erythrocyte properties in both gender

    OpenAIRE

    Hilário, Sandra; Saldanha, Carlota; Martins e Silva, J.

    2003-01-01

    © 2003 – IOS Press. All rights reserved The possibility that erythrocytes may function as a reservoir for noradrenaline and adrenaline and as a modulator of circulating catecholamine concentrations had been suggested. The aim of this work was to study the adrenaline effect on erythrocyte membrane fluidity, acetylcholinesterase (AChE) enzyme activity, P50 and erythrocyte deformability and also to verify if the role of adrenaline on erythrocyte properties is sex-dependent. Blood sample...

  6. Python erythrocytes are resistant to α-hemolysin from Escherichia coli.

    Science.gov (United States)

    Larsen, Casper K; Skals, Marianne; Wang, Tobias; Cheema, Muhammad U; Leipziger, Jens; Praetorius, Helle A

    2011-12-01

    α-Hemolysin (HlyA) from Escherichia coli lyses mammalian erythrocytes by creating nonselective cation pores in the membrane. Pore insertion triggers ATP release and subsequent P2X receptor and pannexin channel activation. Blockage of either P2X receptors or pannexin channels reduces HlyA-induced hemolysis. We found that erythrocytes from Python regius and Python molurus are remarkably resistant to HlyA-induced hemolysis compared to human and Trachemys scripta erythrocytes. HlyA concentrations that induced maximal hemolysis of human erythrocytes did not affect python erythrocytes, but increasing the HlyA concentration 40-fold did induce hemolysis. Python erythrocytes were more resistant to osmotic stress than human erythrocytes, but osmotic stress tolerance per se did not confer HlyA resistance. Erythrocytes from T. scripta, which showed higher osmotic resistance than python erythrocytes, were as susceptible to HlyA as human erythrocytes. Therefore, we tested whether python erythrocytes lack the purinergic signalling known to amplify HlyA-induced hemolysis in human erythrocytes. P. regius erythrocytes increased intracellular Ca²⁺ concentration and reduced cell volume when exposed to 3 mM ATP, indicating the presence of a P2X₇-like receptor. In addition, scavenging extracellular ATP or blocking P2 receptors or pannexin channels reduced the HlyA-induced hemolysis. We tested whether the low HlyA sensitivity resulted from low affinity of HlyA to the python erythrocyte membrane. We found comparable incorporation of HlyA into human and python erythrocyte membranes. Taken together, the remarkable HlyA resistance of python erythrocytes was not explained by increased osmotic resistance, lack of purinergic hemolysis amplification, or differences in HlyA affinity.

  7. Calpain-1 knockout reveals broad effects on erythrocyte deformability and physiology

    Science.gov (United States)

    Wieschhaus, Adam; Khan, Anwar; Zaidi, Asma; Rogalin, Henry; Hanada, Toshihiko; Liu, Fei; De Franceschi, Lucia; Brugnara, Carlo; Rivera, Alicia; Chishti, Athar H.

    2014-01-01

    Pharmacological inhibitors of cysteine proteases have provided useful insights into the regulation of calpain activity in erythrocytes. However, the precise biological function of calpain activity in erythrocytes remains poorly understood. Erythrocytes express calpain-1, an isoform regulated by calpastatin, the endogenous inhibitor of calpains. In the present study, we investigated the function of calpain-1 in mature erythrocytes using our calpain-1-null [KO (knockout)] mouse model. The calpain-1 gene deletion results in improved erythrocyte deformability without any measurable effect on erythrocyte lifespan in vivo. The calcium-induced sphero-echinocyte shape transition is compromised in the KO erythrocytes. Erythrocyte membrane proteins ankyrin, band 3, protein 4.1R, adducin and dematin are degraded in the calcium-loaded normal erythrocytes but not in the KO erythrocytes. In contrast, the integrity of spectrin and its state of phosphorylation are not affected in the calcium-loaded erythrocytes of either genotype. To assess the functional consequences of attenuated cytoskeletal remodelling in the KO erythrocytes, the activity of major membrane transporters was measured. The activity of the K+–Cl− co-transporter and the Gardos channel was significantly reduced in the KO erythrocytes. Similarly, the basal activity of the calcium pump was reduced in the absence of calmodulin in the KO erythrocyte membrane. Interestingly, the calmodulin-stimulated calcium pump activity was significantly elevated in the KO erythrocytes, implying a wider range of pump regulation by calcium and calmodulin. Taken together, and with the atomic force microscopy of the skeletal network, the results of the present study provide the first evidence for the physiological function of calpain-1 in erythrocytes with therapeutic implications for calcium imbalance pathologies such as sickle cell disease. PMID:22870887

  8. Kinetics of viral load and erythrocytic inclusion body formation in pacific herring artificially infected with erythrocytic necrosis virus

    Science.gov (United States)

    Glenn, Jolene A.; Emmenegger, Eveline J.; Grady, Courtney A.; Roon, Sean R.; Gregg, Jacob L.; Conway, Carla M.; Winton, James R.; Hershberger, Paul K.

    2012-01-01

    Viral erythrocytic necrosis (VEN) is a condition that affects marine and anadromous fish species, including herrings and salmonids, in the Atlantic and Pacific oceans. Infection is frequently associated with severe anemia and causes episodic mortality among wild and hatchery fish when accompanied by additional stressors; VEN can be presumptively diagnosed by (1) light microscopic identification of a single characteristic—a round, magenta-colored, 0.8-μm-diameter inclusion body (IB) within the cytoplasm of erythrocytes and their precursors on Giemsa-stained blood films; or (2) observation (via transmission electron microscopy [TEM]) of the causative iridovirus, erythrocytic necrosis virus (ENV), within erythrocytes or their precursors. To better understand the kinetics of VEN, specific-pathogen-free Pacific herring Clupea pallasii were infected with ENV by intraperitoneal injection. At 1, 4, 7, 10, 14, 21, and 28 d postexposure, samples of blood, spleen, and kidney were collected and assessed (1) via light microscopy for the number of intracytoplasmic IBs in blood smears and (2) via TEM for the number of virions within erythrocytes. The mean prevalence of intracytoplasmic IBs in the blood cells increased from 0% at 0–4 d postexposure to 94% at 28 d postexposure. Viral load within circulating red blood cells peaked at 7 d postexposure, fell slightly, and then reached a plateau. However, blood cells observed within the kidney and spleen tissues demonstrated high levels of ENV between 14 and 28 d postexposure. The results indicate that the viral load within erythrocytes does not correlate well with IB prevalence and that the virus can persist in infected fish for more than 28 d.

  9. Janus kinase 3 is expressed in erythrocytes, phosphorylated upon energy depletion and involved in the regulation of suicidal erythrocyte death.

    Science.gov (United States)

    Bhavsar, Shefalee K; Gu, Shuchen; Bobbala, Diwakar; Lang, Florian

    2011-01-01

    Janus kinase 3, a tyrosine kinase expressed in haematopoetic tissues, plays a decisive role in T-lymphocyte survival. JAK3 deficiency leads to (Severe) Combined Immunodeficiency (SCID) resulting from enhanced lymphocyte apoptosis. JAK3 is activated by phosphorylation. Nothing is known about expression of JAK3 in erythrocytes, which may undergo apoptosis-like cell death (eryptosis) characterized by cell membrane scrambling with phosphatidylserine exposure and cell shrinkage. Triggers of eryptosis include energy depletion. The present study utilized immunohistochemistry and confocal microscopy to test for JAK3 expression and phosphorylation, and FACS analysis to determine phosphatidylserine exposure (annexin binding) and cell volume (forward scatter). As a result, JAK3 was expressed in erythrocytes and phosphorylated following 24h and 48h glucose depletion. Forward scatter was slightly but significantly smaller in erythrocytes from JAK3-deficient mice (jak3(-/-)) than in erythrocytes from wild type mice (jak3(+/+)). Annexin V binding was similarly low in both genotypes. The JAK3 inhibitors WHI-P131/JANEX-1 (4-(4'-Hydroxyphenyl)amino-6,7-dimethoxyquinazoline, 156μM) and WHI-P154 (4-[(3'-Bromo-4'-hydroxyphenyl)amino]-6,7-dimethoxyquinazoline, 11.2μM) did not significantly modify annexin V binding or forward scatter. Glucose depletion increased annexin V binding, an effect significantly blunted in jak3(-/-) erythrocytes and in the presence of the JAK3 inhibitors. The observations disclose a completely novel role of Janus kinase 3, i.e. the triggering of cell membrane scrambling in energy depleted erythrocytes. Copyright © 2011 S. Karger AG, Basel.

  10. [Physical essence of erythrocytic sedimentation rate in the gravitation field of the earth].

    Science.gov (United States)

    Cherniĭ, A N

    2009-01-01

    The erythrocytic sedimentation rate method has been long known in medicine and extensively used in laboratory practice in tuberculosis facilities. However, many authors note that the erythrocytic sedimentation rate phenomenon has not clearly understood. By applying the total theory of relativity and quantum mechanics, the author discloses the physical essence of erythrocytic sedimentation in the gravitation field of the Earth.

  11. Determination of alternative pathway of complement activity in mouse serum using rabbit erythrocytes

    NARCIS (Netherlands)

    Dijk, H. van; Rademaker, P.M.; Willers, J.M.N

    1980-01-01

    Rabbit, mouse and sheep erythrocytes expressing different concentrations of membrane sialic acid were used to study possible modes of activation of the alternative complement (C) pathway in mouse, human and guinea pig serum. Mouse erythrocytes activated only human serum, whereas rabbit erythrocytes

  12. An erythrocytic virus of the brazilian tree-frog, Phrynohyas venulosa

    Directory of Open Access Journals (Sweden)

    A. P. Alves de Matos

    1995-10-01

    Full Text Available Blood erythrocytes of Brazilian tree-frogs, Phrynohyas venulosa were found to frequently contain single, small, densely staining inclusions. Electron microscopy showed these to be icosahedral viral particles which measured from 250-280 nm in diameter; they were devoid of an envelope, and thus differed from previously described viruses of frog erythrocytes. The infected erythrocytes lacked a crystalline body.

  13. The involvement of erythrocyte metabolism in organismal homeostasis in health and disease

    NARCIS (Netherlands)

    Bosman, G.J.C.G.M.

    2016-01-01

    Historically, study of erythrocyte homeostasis has focussed on the survival of erythrocytes in the blood bank and, especially in pathological circumstances, on the mechanisms leading to accelerated aging and removal from the circulation. Recent proteomic and metabolomic data suggest that erythrocyte

  14. Experiment study and FEM simulation on erythrocytes under linear stretching of optical micromanipulation

    Science.gov (United States)

    Liu, Ying; Song, Huadong; Zhu, Panpan; Lu, Hao; Tang, Qi

    2017-08-01

    The elasticity of erythrocytes is an important criterion to evaluate the quality of blood. This paper presents a novel research on erythrocytes' elasticity with the application of optical tweezers and the finite element method (FEM) during blood storage. In this work, the erythrocytes with different in vitro times were linearly stretched by trapping force using optical tweezers and the time dependent elasticity of erythrocytes was investigated. The experimental results indicate that the membrane shear moduli of erythrocytes increased with the increasing in vitro time, namely the elasticity was decreasing. Simultaneously, an erythrocyte shell model with two parameters (membrane thickness h and membrane shear modulus H) was built to simulate the linear stretching states of erythrocytes by the FEM, and the simulations conform to the results obtained in the experiment. The evolution process was found that the erythrocytes membrane thicknesses were decreasing. The analysis assumes that the partial proteins and lipid bilayer of erythrocyte membrane were decomposed during the in vitro preservation of blood, which results in thin thickness, weak bending resistance, and losing elasticity of erythrocyte membrane. This study implies that the FEM can be employed to investigate the inward mechanical property changes of erythrocyte in different environments, which also can be a guideline for studying the erythrocyte mechanical state suffered from different diseases.

  15. Erythrocyte ageing in vivo and in vitro: structural aspects and implications for transfusion.

    NARCIS (Netherlands)

    Bosman, G.J.C.G.M.; Werre, J.M.; Willekens, F.L.A.; Novotny, V.M.J.

    2008-01-01

    Erythrocyte transfusion is essential in conditions of large blood loss, of inadequate bone marrow production and of increased erythrocyte breakdown. The structural and biochemical changes that erythrocytes go through during storage, probably associated with the disappearance of up to 30% of the

  16. ABO Blood Groups Influence Macrophage-mediated Phagocytosis of Plasmodium falciparum-infected Erythrocytes

    Science.gov (United States)

    Branch, Donald R.; Hult, Annika K.; Olsson, Martin L.; Liles, W. Conrad; Cserti-Gazdewich, Christine M.; Kain, Kevin C.

    2012-01-01

    Erythrocyte polymorphisms associated with a survival advantage to Plasmodium falciparum infection have undergone positive selection. There is a predominance of blood group O in malaria-endemic regions, and several lines of evidence suggest that ABO blood groups may influence the outcome of P. falciparum infection. Based on the hypothesis that enhanced innate clearance of infected polymorphic erythrocytes is associated with protection from severe malaria, we investigated whether P. falciparum-infected O erythrocytes are more efficiently cleared by macrophages than infected A and B erythrocytes. We show that human macrophages in vitro and mouse monocytes in vivo phagocytose P. falciparum-infected O erythrocytes more avidly than infected A and B erythrocytes and that uptake is associated with increased hemichrome deposition and high molecular weight band 3 aggregates in infected O erythrocytes. Using infected A1, A2, and O erythrocytes, we demonstrate an inverse association of phagocytic capacity with the amount of A antigen on the surface of infected erythrocytes. Finally, we report that enzymatic conversion of B erythrocytes to type as O before infection significantly enhances their uptake by macrophages to observed level comparable to that with infected O wild-type erythrocytes. These data provide the first evidence that ABO blood group antigens influence macrophage clearance of P. falciparum-infected erythrocytes and suggest an additional mechanism by which blood group O may confer resistance to severe malaria. PMID:23071435

  17. Effect of serum from various animal species on erythrocyte attachment of endotoxins and other bacterial antigens.

    Science.gov (United States)

    Praino, M; Neter, E

    1977-12-01

    Lipopolysaccharide O antigens (endotoxins) and other bacterial antigens readily attach to erythrocytes in vitro. This attachment is prevented by certain mammalian and avian sera. In this study, the inhibitory capacity of sera from lower animals was compared with that of higher animals for a total of 30 species. Antigens and the corresponding antisera included both crude O antigens and purified lipopolysaccharide preparations, the common enterobacterial antigen from Escherichia coli O14, the Vi antigen from Citrobacter ballerup, the polyribose-phosphate antigen from Haemophilus influenzae type b, and the crude teichoic acid antigen from Staphylococcus aureus. Antigen and serum mixtures were incubated at 37 degrees C for 30 min and used for erythrocyte modification; failure of hemagglutination by homologous bacterial antiserum provided evidence of inhibitory capacity. Sera from the classes Mammalia and Aves were very strong inhibitors; those of Reptilia and Osteichthyes were moderate in activity, displaying variation within the classes; those of Amphibia and Chondrichthyes were minimal inhibitors; and those of Merostomata, Crustacea, and Lamellibranchiata displayed questionable or no inhibitory capacity. Inhibitory sera were active with all antigens tested. The findings suggest evolution of inhibitory factors consistent with the theory of two diverging lines of animal phylogeny based on embryological criteria and closely parallel the observations of an endotoxin-altering capacity in vertebrate sera that is not found in invertebrate sera or hemolymph.

  18. Transbilayer movement of various phosphatidylcholine species in intact human erythrocytes

    NARCIS (Netherlands)

    van Meer, G.|info:eu-repo/dai/nl/068570368; op den Kamp, J.A.F.

    1982-01-01

    Phosphatidylcholine specific phospholipid exchange protein was used to introduce (14C)-labeled phosphatidylcholine of different fatty acyl compositions into the intact human erythrocyte. Hydrolysis by a combination of phospholipase A2 and sphingomyelinase was applied to prove that originally all

  19. Dyslipidemia, altered erythrocyte fatty acids and selenium are ...

    African Journals Online (AJOL)

    Dyslipidemia, reduced omega-3 and -6 fatty acids and antioxidative nutrients are modulatory risk factors associated with dementia. Diet, genetics and environment interact with nutritional metabolism and susceptibility to neurodegeneration. This study investigated the relationship between erythrocyte fatty acids and selected ...

  20. Determination of molecular species of lecithin from erythrocytes and plasma

    NARCIS (Netherlands)

    Golde, L.M.G. van; Tomasi, V.; Deenen, L.L.M. van

    The molecular species of lecithin from erythrocyte and plasma of man and rabbit were determined after conversion of the lecithins into diglycerides by means of hydrolysis with phospholipase C. The resultant diglycerides were separated by thin-layer chromatography on silica impregnated with silver

  1. Erythrocyte indices and serum biochemical constituents of broiler ...

    African Journals Online (AJOL)

    One hundred and twenty (120) four weeks old Ross breed broiler finisher birds were used to study the effect of feeding maggot meal as a replacement for fish meal on erythrocyte indices and serum biochemical constituents. The birds were divided into 5 treatment groups identified as T1, T2, T3 , T4 and T5 with 24 birds per ...

  2. Erythrocyte phospholipid and polyunsaturated fatty acid composition in diabetic retinopathy.

    Science.gov (United States)

    Koehrer, Philippe; Saab, Sarah; Berdeaux, Olivier; Isaïco, Rodica; Grégoire, Stéphane; Cabaret, Stéphanie; Bron, Alain M; Creuzot-Garcher, Catherine P; Bretillon, Lionel; Acar, Niyazi

    2014-01-01

    Long chain polyunsaturated fatty acids (LCPUFAs) including docosahexaenoic acid and arachidonic acid are suspected to play a key role in the pathogenesis of diabetes. LCPUFAs are known to be preferentially concentrated in specific phospholipids termed as plasmalogens. This study was aimed to highlight potential changes in the metabolism of phospholipids, and particularly plasmalogens, and LCPUFAs at various stages of diabetic retinopathy in humans. We performed lipidomic analyses on red blood cell membranes from controls and mainly type 2 diabetes mellitus patients with or without retinopathy. The fatty acid composition of erythrocytes was determined by gas chromatography and the phospholipid structure was determined by liquid chromatography equipped with an electrospray ionisation source and coupled with a tandem mass spectrometer (LC-ESI-MS/MS). A significant decrease in levels of docosahexaenoic acid and arachidonic acid in erythrocytes of diabetic patients with or without retinopathy was observed. The origin of this decrease was a loss of phosphatidyl-ethanolamine phospholipids esterified with these LCPUFAs. In diabetic patients without retinopathy, this change was balanced by an increase in the levels of several phosphatidyl-choline species. No influence of diabetes nor of diabetic retinopathy was observed on the concentrations of plasmalogen-type phospholipids. Diabetes and diabetic retinopathy were associated with a reduction of erythrocyte LCPUFAs in phosphatidyl-ethanolamines. The increase of the amounts of phosphatidyl-choline species in erythrocytes of diabetic patients without diabetic retinopathy might be a compensatory mechanism for the loss of LC-PUFA-rich phosphatidyl-ethanolamines.

  3. Erythrocyte phospholipid and polyunsaturated fatty acid composition in diabetic retinopathy.

    Directory of Open Access Journals (Sweden)

    Philippe Koehrer

    Full Text Available Long chain polyunsaturated fatty acids (LCPUFAs including docosahexaenoic acid and arachidonic acid are suspected to play a key role in the pathogenesis of diabetes. LCPUFAs are known to be preferentially concentrated in specific phospholipids termed as plasmalogens. This study was aimed to highlight potential changes in the metabolism of phospholipids, and particularly plasmalogens, and LCPUFAs at various stages of diabetic retinopathy in humans.We performed lipidomic analyses on red blood cell membranes from controls and mainly type 2 diabetes mellitus patients with or without retinopathy. The fatty acid composition of erythrocytes was determined by gas chromatography and the phospholipid structure was determined by liquid chromatography equipped with an electrospray ionisation source and coupled with a tandem mass spectrometer (LC-ESI-MS/MS. A significant decrease in levels of docosahexaenoic acid and arachidonic acid in erythrocytes of diabetic patients with or without retinopathy was observed. The origin of this decrease was a loss of phosphatidyl-ethanolamine phospholipids esterified with these LCPUFAs. In diabetic patients without retinopathy, this change was balanced by an increase in the levels of several phosphatidyl-choline species. No influence of diabetes nor of diabetic retinopathy was observed on the concentrations of plasmalogen-type phospholipids.Diabetes and diabetic retinopathy were associated with a reduction of erythrocyte LCPUFAs in phosphatidyl-ethanolamines. The increase of the amounts of phosphatidyl-choline species in erythrocytes of diabetic patients without diabetic retinopathy might be a compensatory mechanism for the loss of LC-PUFA-rich phosphatidyl-ethanolamines.

  4. In vitro effects of aspirin and paracetamol on human erythrocyte ...

    African Journals Online (AJOL)

    The activity of glutathione-S-transferase of human erythrocytes was monitored spectrophotometically in the presence and absence of two analgesics (aspirin and paracetamol). Five different concentrations (1.0, 3.0, 5.0, 7.0, 9.0 and 10.0 mg/ml) of each analgesic were used which covers the reported therapeutic and toxic ...

  5. influence of pregnancy on some erythrocyte biochemical profiles in ...

    African Journals Online (AJOL)

    Femi Olaleye

    of Na2EDTA-2-mercaptoethanol. Preparation of lysate for some clinical chemical parameters assays. The haemolysate was prepared as described by Wilson and Dixon (1991). The erythrocyte count of the lithium chloride-washed cells was determined as described by. Jam (1986), after thorough mixing, 108 red blood cells.

  6. Erratum Detergent-resistant membranes in human erythrocytes and ...

    Indian Academy of Sciences (India)

    Unknown

    Figure 3. Immunodetection of flotillin-2 and band 3 in DRMs isolated from erythrocyte ghosts by various treatments. Flotillin-2. (left) and band 3 (right) Western blotting in ten fractions of 0⋅5 ml each, obtained from the sucrose gradients described in figure 2 and numbered from top to bottom. Flotillin-2 is enriched in DRMs ...

  7. Role of aminotransferases in glutamate metabolism of human erythrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Ellinger, James J. [University of Wisconsin-Madison, Department of Biochemistry (United States); Lewis, Ian A. [Princeton University, Lewis-Sigler Institute for Integrative Genomics (United States); Markley, John L., E-mail: markley@nmrfam.wisc.edu [University of Wisconsin-Madison, Department of Biochemistry (United States)

    2011-04-15

    Human erythrocytes require a continual supply of glutamate to support glutathione synthesis, but are unable to transport this amino acid across their cell membrane. Consequently, erythrocytes rely on de novo glutamate biosynthesis from {alpha}-ketoglutarate and glutamine to maintain intracellular levels of glutamate. Erythrocytic glutamate biosynthesis is catalyzed by three enzymes, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and glutamine aminohydrolase (GA). Although the presence of these enzymes in RBCs has been well documented, the relative contributions of each pathway have not been established. Understanding the relative contributions of each biosynthetic pathway is critical for designing effective therapies for sickle cell disease, hemolytic anemia, pulmonary hypertension, and other glutathione-related disorders. In this study, we use multidimensional {sup 1}H-{sup 13}C nuclear magnetic resonance (NMR) spectroscopy and multiple reaction mode mass spectrometry (MRM-MS) to measure the kinetics of de novo glutamate biosynthesis via AST, ALT, and GA in intact cells and RBC lysates. We show that up to 89% of the erythrocyte glutamate pool can be derived from ALT and that ALT-derived glutamate is subsequently used for glutathione synthesis.

  8. Erythrocyte osmotic fragility of pigs administered ascorbic acid and ...

    African Journals Online (AJOL)

    PRECIOUS

    2010-01-11

    Jan 11, 2010 ... The experiment was carried out with the aim of investigating the effect of an antioxidant ascorbic acid on erythrocyte osmotic fragility of pigs transported by road for 4 h during the harmattan season. 16 pigs administered with ascorbic acid at the dose of 250 mg/kg per os and individually served as.

  9. Influence of haemoglobin solution from sickled erythrocytes on ...

    African Journals Online (AJOL)

    There are conflicting reports concerning vascular reactivity changes in sickle cell anaemia (SCA). The goal of the present study was to examine possible interactions between components of sickle erythrocytes and the vascular endothelium, that may alter vascular reactivity in isolated rabbit carotid arteries.

  10. Erythrocyte indices of iron status in children with cyanotic congenital ...

    African Journals Online (AJOL)

    Background Iron (Fe) deficiency is a known feature of cyanotic congenital heart disease (CCHD) and may worsen symptoms. The prevalence of iron deficiency among children with CCHD at the University College Hospital (UCH), Ibadan is unknown. Erythrocyte indices of iron status are easier and less expensive to ...

  11. Erythrocyte Sodium Sensitivity and Eryptosis in Chronic Hemodialysis Patients

    Directory of Open Access Journals (Sweden)

    Anna Meyring-Wösten

    2017-06-01

    Full Text Available Background/Aims: In hemodialysis (HD patients the endothelial and erythrocyte glycocalyx is impaired which in turn correlates with elevated erythrocyte sodium sensitivity (ESS. Additionally, apoptotic erythrocyte death (eryptosis, characterized by phosphatidylserine (PS exposure on the cell surface, is increased in this population. We aimed to explore the relationship of ESS and eryptosis. Methods: Blood samples were collected from 11 healthy controls and 20 chronic HD patients before and after midweek HD. ESS was quantified by the salt blood test. PS-exposure, intracellular reactive oxygen species (ROS of erythrocytes and reticulocytes were assessed by flow cytometry. Results: Compared to controls ESS was significantly higher in HD patients preHD and did not change during treatment. The percentage of eryptotic cells did not differ between controls and patients preHD. However, eryptosis decreased during HD. ESS and eryptosis were uncorrelated, while eryptosis was positively correlated with intracellular ROS and percent reticulocytes. Conclusions: Higher ESS levels in HD patients indicate a pathologic glycocalyx. ESS and eryptosis were not correlated. The decreased eryptosis postHD may possibly be related to dialytic uremic toxin removal, but is likely multifactorial. The relationship between eryptosis and intracellular ROS warrants further research.

  12. Effect of garlic's mode of administration on erythrocytes and plasma ...

    African Journals Online (AJOL)

    Garlic preparations are recognized as hypolipidemic, cardioprotective and antihypertensive agents. However, there are some discrepancies about the beneficial effects of garlic according to dosage and mode of administration. We aimed to determine the ability of high dosage garlic (5 g/kg bw) to modulate erythrocytes and ...

  13. Improved Erythrocyte Osmotic Fragility and Packed Cell Volume ...

    African Journals Online (AJOL)

    Improved Erythrocyte Osmotic Fragility and Packed Cell Volume following administration of Aloe barbadensis Juice Extract in Rats. ... Abstract. Aloe barbadensis is a popular house plant that has a long history of a multipurpose folk remedy. ... Keywords: osmotic fragility, packed cell volume, haemoglobin, Aloe vera ...

  14. Mercury chloride-induced oxidative stress in human erythrocytes ...

    African Journals Online (AJOL)

    ONOS

    2010-01-25

    Jan 25, 2010 ... Key words: Mercury chloride, vitamins C and E, oxidative stress, erythrocytes, in vitro. ... of free radicals induced by oxidative damage to lipids and lipoproteins in various cellular ... metals toxicity in different experimental systems ..... vitamins C, E and beta carotene aganist gamma-ray-induced DNA damage ...

  15. A comparative analysis of kinetic models of erythrocyte glycolysis.

    NARCIS (Netherlands)

    du Preez, F.B.; Conradie, R.; Penkler, G.P.; Holm, K.; van dooren, F.L.J.; Snoep, J.L.

    2008-01-01

    Since the 1970s, with Heinrich as a pioneer in the field, numerous kinetic models of erythrocyte glycolysis have been constructed. A functional comparison of eight of these models indicates that the production of ATP and GSH in the red blood cell is largely controlled by the demand reactions. The

  16. Erythrocyte Antioxidant Protection of Rose Hips (Rosa spp.

    Directory of Open Access Journals (Sweden)

    C. Widén

    2012-01-01

    Full Text Available Rose hips are popular in health promoting products as the fruits contain high content of bioactive compounds. The aim of this study was to investigate whether health benefits are attributable to ascorbic acid, phenols, or other rose-hip-derived compounds. Freeze-dried powder of rose hips was preextracted with metaphosphoric acid and the sample was then sequentially eluted on a C18 column. The degree of amelioration of oxidative damage was determined in an erythrocyte in vitro bioassay by comparing the effects of a reducing agent on erythrocytes alone or on erythrocytes pretreated with berry extracts. The maximum protection against oxidative stress, 59.4±4.0% (mean ± standard deviation, was achieved when incubating the cells with the first eluted meta-phosphoric extract. Removal of ascorbic acid from this extract increased the protection against oxidative stress to 67.9±1.9%. The protection from the 20% and 100% methanol extracts was 20.8±8.2% and 5.0±3.2%, respectively. Antioxidant uptake was confirmed by measurement of catechin by HPLC-ESI-MS in the 20% methanol extract. The fact that all sequentially eluted extracts studied contributed to protective effects on the erythrocytes indicates that rose hips contain a promising level of clinically relevant antioxidant protection.

  17. Changes in erythrocytic deformability and plasma viscosity in neonatal ictericia.

    Science.gov (United States)

    Bonillo-Perales, A; Muñoz-Hoyos, A; Martínez-Morales, A; Molina-Carballo, A; Uberos-Fernández, J; Puertas-Prieto, A

    1999-01-01

    We studied 45 full-term newborns divided into 3 groups. Group 1: 17 newborns with bilirubin ictericia (bilirubin 11-20 mg/dL) and Group 3: 10 newborns with moderate hemolytic ictericia needing exchange transfusion. The following were studied: erythrocytic deformability, plasma viscosity, plasmatic osmolarity, seric bilirubin, bilirubin/albumin ratio, free fatty acids and corpuscular volume of the erythrocytes. In full-term newborns, the following are risk factors for increased erythrocytic rigidity: neonatal hemolytic illness (p = 0.004, odds ratio: 7.02), increases in total bilirubin (p = 0.02, odds ratio: 4.3) and increases in the bilirubin/albumin ratio (p = 0.025, odds ratio: 4.25). Furthermore, the most important risk factor for high plasma viscosity is also neonatal hemolytic illness (p = 0.01, odds ratio: 2.30). The role of total bilirubin is also important (p = 0.09, odds ratio: 2.10), while that of the bilirubin/albumin ratio (p = 0.012, NS) is less so. The greater the hemolysis, the greater the erythrocytic rigidity and plasma viscosity (p ictericia, hemolytic illness and increases in the bilirubin/albumin ratio are accompanied by rheological alterations that could affect cerebral microcirculation and cause a neurological deficit not exclusively related to the levels of bilirubin in plasma.

  18. Investigation of the peripheral erythrocytes of Cyprinus carpio

    African Journals Online (AJOL)

    Clastogenic effects of home wastes and agricultural contaminates of Lake Uluabat ("40°11'41.38"N, "28°27'08.40"E) were investigated in peripheral erythrocytes of Cyprinus carpio. Examination of blood smears showed that the formation of micronuclei was significantly increased (f = 21.89, df = 3) with p value > 0.001during ...

  19. Modulatory Role of Antioxidant Vitamins C and E on Erythrocyte ...

    African Journals Online (AJOL)

    Vitamin C and E supplements were administered to sodium nitrate-treated rats in order to examine the possible ameliorative effects of these antioxidants on erythrocyte osmotic fragility. Seventy adult Wistar rats were randomly divided into seven groups (n=10) and administered drugs or distilled water orally using a metallic ...

  20. Detergent-resistant membranes in human erythrocytes and their ...

    Indian Academy of Sciences (India)

    Unknown

    Introduction. Lipid microdomains enriched in cholesterol and sphin- golipids are thought to exist in vivo in the membranes of living cells (Edidin 1997, 2001; Brown and London. 1998; Pike 2004). These structures are sites of ...... induced in erythrocytes infected by malaria parasites; Cell. Microbiol. 4 383–395. Heerklotz H ...

  1. Lipid Peroxidation And Erythrocyte Fragility In Poorly Controlled ...

    African Journals Online (AJOL)

    Thus there is increased interest in determining the oxidative status of persons with diabetes. Objectives: This study was carried out to determine if the plasma oxidative stress status is high in diabetics (especially those that are poorly controlled) and to determine the effect on erythrocyte stability. Methods: Plasma levels of ...

  2. Procalcitonin and white blood cell count (WBC), erythrocyte ...

    African Journals Online (AJOL)

    The present prospective observational study aimed to determine the correlation between procalcitonin (PCT) and white blood cell count (WBC), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in toddlers before and after treatment. Moreover, 50 patients aged 1 to 36 months who were hospitalized at the ...

  3. In vitro Erythrocyte Haemolysis Inhibition Properties of Senna ...

    African Journals Online (AJOL)

    The objective of this work was to study the antioxidant properties, of this plant using an erythrocyte haemolysis inhibition assay, because one way to justify the traditional anticancer uses can be through the concept of antioxidant effect. Crude extracts from leaves and bark of S. singueana were prepared by maceration with ...

  4. Erythrocytes for Drug Delivery and their Applications: A Review ...

    African Journals Online (AJOL)

    Recent advances have witnessed the emergence of an increasing number of novel carriers for the delivery of drugs. In this manuscript, we review and discuss the blood cellular carriers because of their great biocompatibility and thus a reduction in side effects. Our emphasis was on the erythrocyte because recent studies ...

  5. Clinical utility of the erythrocyte sedimentation rate test and ...

    African Journals Online (AJOL)

    Background: The erythrocyte sedimentation rate (ESR) is a relatively non-specific test that is often ignored during the diagnosis and monitoring of disease. However, in recent times, the test is often requested alongside haemoglobin electrophoretic pattern as pre marital test. This study was aimed at determining the ESR ...

  6. Erythrocyte osmotic fragility of pigs administered ascorbic acid and ...

    African Journals Online (AJOL)

    The experiment was carried out with the aim of investigating the effect of an antioxidant ascorbic acid on erythrocyte osmotic fragility of pigs transported by road for 4 h during the harmattan season. 16 pigs administered with ascorbic acid at the dose of 250 mg/kg per os and individually served as experimental animals and ...

  7. Influence of pregnancy on some erythrocyte biochemical profiles in ...

    African Journals Online (AJOL)

    One billion erythrocytes lysate samples obtained from pregnant (28-day old) and non-pregnant groups or New Zealand white Chinchilla rabbits (eight rabbits per group) were analysed to determine the influence of pregnancy on the profile of some of the intracellular electrolytes, enzymes, lipids, proteins and rnetabolites.

  8. Associations of erythrocyte fatty acid patterns with insulin resistance

    Science.gov (United States)

    Background: Synergistic and/or additive effects on cardiometabolic risk may be missed by examining individual fatty acids (FA). A pattern analysis may be a more useful approach. As well, it remains unclear whether erythrocyte fatty acid composition relates to insulin resistance among Hispanic/Latino...

  9. Erythrocyte membrane fatty acids in multiple sclerosis patients and ...

    African Journals Online (AJOL)

    The risk of developing multiple sclerosis (MS) is associated with increased dietary intake of saturated fatty acids. For many years it has been suspected that this disease might be associated with an imbalance between unsaturated and saturated fatty acids. We determined erythrocyte membrane fatty acids levels in Hot ...

  10. Unexpectedly long half-life of metformin elimination in cases of metformin accumulation.

    Science.gov (United States)

    Kajbaf, F; Bennis, Y; Hurtel-Lemaire, A-S; Andréjak, M; Lalau, J-D

    2016-01-01

    In a study of the oral administration of a single dose of metformin to healthy participants, the estimated half-life (t½ ) for the elimination of the drug from erythrocytes was found to be 23.4 h (compared with 2.7 h for metformin in plasma). However, these pharmacokinetic indices have not been well defined in metformin accumulation. We systematically reviewed all the data on plasma and erythrocyte metformin assays available in our centre. We then selected patients with a plasma metformin concentration ≥ 5 mg/l and in whom the metformin concentration had been remeasured once or more at least 5 days after admission. Twelve patients met the aforementioned criteria. All but one of these patients displayed generally severe lactic acidosis on admission (mean ± sd pH and lactate: 6.88 ± 0.35 and 14.8 ± 6.56 mmol/l, respectively) and 11 were treated with dialysis. The mean ± sd time interval between the first and last blood sample collections for metformin measurement was 8.3 ± 3.2 days (range 5-14 days). Five days after the first sample had been collected, metformin was still detectable in plasma and in erythrocytes in all patients. Metformin remained detectable for up to 13 days (both in plasma and in erythrocytes). The estimated mean terminal t½ for metformin in plasma and erythrocytes was 51.9 and 43.4 h, respectively. The prolonged elimination of accumulated metformin (even after dialysis therapy) challenges the traditional view that the drug clears rapidly because of a short half-life in plasma. © 2015 The Authors. Diabetic Medicine © 2015 Diabetes UK.

  11. Differential nitrate accumulation, nitrate reduction, nitrate reductase ...

    African Journals Online (AJOL)

    use

    2011-12-07

    Dec 7, 2011 ... biosynthesis. Carbohydrate metabolism produces both the carbon skeletons and ferredoxin for nitrate assimilation. Inhibition of photosynthesis prevents the production of the reduced ferredoxin required for nitrite reduction in chloroplasts, which leads to nitrate and nitrite accumulation (Commichau et al., ...

  12. Micronucleated Erythrocytes in Peripheral Blood from Neonate Rats Exposed by Breastfeeding to Cyclophosphamide, Colchicine, or Cytosine-Arabinoside

    Directory of Open Access Journals (Sweden)

    Belinda C. Gómez-Meda

    2016-01-01

    Full Text Available Genotoxic exposure to chemical substances is common, and nursing mothers could transmit harmful substances or their metabolites to their offspring through breast milk. We explored the possibility of determining genotoxic effects in the erythrocytes of breastfeeding rat pups whose mothers received a genotoxic compound while nursing. Ten groups of female rats and five pups per dam were studied. The control group received sterile water, and the experimental groups received one of three different doses of cyclophosphamide, colchicine, or cytosine-arabinoside. Blood smears were prepared from samples taken from each dam and pup every 24 h for six days. There were increased numbers of micronucleated erythrocytes (MNEs and micronucleated polychromatic erythrocytes (MNPCEs in the samples from pups in the experimental groups (P<0.02 and increased MNPCE frequencies in the samples from the dams (P<0.05. These results demonstrate the vertical transmission of the genotoxic effect of the compounds tested. In conclusion, assessing MNEs in breastfeeding neonate rats to assess DNA damage may be a useful approach for identifying genotoxic compounds and/or cytotoxic effects. This strategy could help in screening for therapeutic approaches that are genotoxic during the lactation stage and these assessments might also be helpful for developing preventive strategies to counteract harmful effects.

  13. Micronucleated Erythrocytes in Peripheral Blood from Neonate Rats Exposed by Breastfeeding to Cyclophosphamide, Colchicine, or Cytosine-Arabinoside

    Science.gov (United States)

    Bañales-Martínez, Luis R.; Lemus-Varela, María de Lourdes; Trujillo, Xóchitl; Sánchez-Parada, María G.; Armendáriz-Borunda, Juan; Zúñiga-González, Guillermo M.

    2016-01-01

    Genotoxic exposure to chemical substances is common, and nursing mothers could transmit harmful substances or their metabolites to their offspring through breast milk. We explored the possibility of determining genotoxic effects in the erythrocytes of breastfeeding rat pups whose mothers received a genotoxic compound while nursing. Ten groups of female rats and five pups per dam were studied. The control group received sterile water, and the experimental groups received one of three different doses of cyclophosphamide, colchicine, or cytosine-arabinoside. Blood smears were prepared from samples taken from each dam and pup every 24 h for six days. There were increased numbers of micronucleated erythrocytes (MNEs) and micronucleated polychromatic erythrocytes (MNPCEs) in the samples from pups in the experimental groups (P < 0.02) and increased MNPCE frequencies in the samples from the dams (P < 0.05). These results demonstrate the vertical transmission of the genotoxic effect of the compounds tested. In conclusion, assessing MNEs in breastfeeding neonate rats to assess DNA damage may be a useful approach for identifying genotoxic compounds and/or cytotoxic effects. This strategy could help in screening for therapeutic approaches that are genotoxic during the lactation stage and these assessments might also be helpful for developing preventive strategies to counteract harmful effects. PMID:28018917

  14. INDUSTRIAL HYDRAULIC ACCUMULATORS AND APPLICATION CIRCUITS

    Directory of Open Access Journals (Sweden)

    Mustafa GÖLCÜ

    2002-01-01

    Full Text Available Important developments in industrial hydraulic technologies extended their application areas including big power transmission systems. Efficient and powerful systems have been developed using sensitive control units. However, it is necessary to provide safe operating working conditions since some systems can not work properly in some situations. For instance, lack of the fluid in the system or leakage of the fluid from the system may cause serious damage in the circuit. When the pressure reaches the high levels, instantaneous shock strokes may also occur. Hydraulic accumulators are used to prevent such kind of problems. In this study, types of accumulators used in hydraulic circuits are introduced and necessary formulas for selection of the accumulators are presented with an example. The usage of accumulators in different circuits is shown with figures.

  15. Interaction of selected anthocyanins with erythrocytes and liposome membranes.

    Science.gov (United States)

    Bonarska-Kujawa, Dorota; Pruchnik, Hanna; Kleszczyńska, Halina

    2012-06-01

    Anthocyanins are one of the main flavonoid groups. They are responsible for, e.g., the color of plants and have antioxidant features and a wide spectrum of medical activity. The subject of the study was the following compounds that belong to the anthocyanins and which can be found, e.g., in strawberries and chokeberries: callistephin chloride (pelargonidin-3-O-glucoside chloride) and ideain chloride (cyanidin-3-O-galactoside chloride). The aim of the study was to determine the compounds' antioxidant activity towards the erythrocyte membrane and changes incurred by the tested anthocyanins in the lipid phase of the erythrocyte membrane, in liposomes composed of erythrocyte lipids and in DPPC, DPPC/cholesterol and egg lecithin liposomes. In particular, we studied the effect of the two selected anthocyanins on red blood cell morphology, on packing order in the lipid hydrophilic phase, on fluidity of the hydrophobic phase, as well as on the temperature of phase transition in DPPC and DPPC/cholesterol liposomes. Fluorimetry with the Laurdan and Prodan probes indicated increased packing density in the hydrophilic phase of the membrane in the presence of anthocyanins. Using the fluorescence probes DPH and TMA-DPH, no effect was noted inside the hydrophobic phase of the membrane, as the lipid bilayer fluidity was not modified. The compounds slightly lowered the phase transition temperature of phosphatidylcholine liposomes. The study has shown that both anthocyanins are incorporated into the outer region of the erythrocyte membrane, affecting its shape and lipid packing order, which is reflected in the increasing number of echinocytes. The investigation proved that the compounds penetrate only the outer part of the external lipid layer of liposomes composed of erythrocyte lipids, DPPC, DPPC/cholesterol and egg lecithin lipids, changing its packing order. Fluorimetry studies with DPH-PA proved that the tested anthocyanins are very effective antioxidants. The antioxidant

  16. Stimulation of Suicidal Erythrocyte Death by Phosphatase Inhibitor Calyculin A

    Directory of Open Access Journals (Sweden)

    Mustafa Almasry

    2016-11-01

    Full Text Available Background/Aims: The serine/threonine protein phosphatase 1 and 2a inhibitor Calyculin A may trigger suicidal death or apoptosis of tumor cells. Similar to apoptosis of nucleated cells, erythrocytes may enter eryptosis, the suicidal erythrocyte death characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include increase of cytosolic Ca2+ activity ([Ca2+] i. Eryptosis is fostered by activation of staurosporine sensitive protein kinase C, SB203580 sensitive p38 kinase, and D4476 sensitive casein kinase. Eryptosis may further involve zVAD sensitive caspases. The present study explored, whether Calyculin A induces eryptosis and, if so, whether its effect requires Ca2+ entry, kinases and/or caspases Methods: Phosphatidylserine exposure at the cell surface was estimated from annexin-V-binding, cell volume from forward scatter, and [Ca2+] i from Fluo-3 fluorescence, as determined by flow cytometry. Results: A 48 hours exposure of human erythrocytes to Calyculin A (≥ 2.5 nM significantly increased the percentage of annexin-V-binding cells, significantly decreased forward scatter and significantly increased Fluo-3 fluorescence. The effect of Calyculin A on annexin-V-binding was significantly blunted by removal of extracellular Ca2+, by staurosorine (1 µM, SB203580 (2 µM, D4476 (10 µM, and zVAD (10 µM. Conclusions: Calyculin A triggers cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect at least in part requiring Ca2+ entry, kinase activity and caspase activation.

  17. Blood erythrocyte and hemoglobin concentrations in premature adrenarche.

    Science.gov (United States)

    Utriainen, Pauliina; Jääskeläinen, Jarmo; Voutilainen, Raimo

    2013-01-01

    Premature adrenarche (PA) is characterized by an earlier than normal increase in adrenocortical androgen production, and it is associated with increased serum IGF-I concentrations. Both the GH-IGF system and androgens, particularly testosterone, are known to enhance erythropoiesis. Our objective was to test the hypothesis that blood erythrocyte count and blood hemoglobin (B-Hb) concentration are increased in PA. Sixty-four prepubertal children (10 boys) with clinically and biochemically defined PA and 62 healthy prepubertal controls (10 boys) participating in our Premature Adrenarche study were examined, and a fasting blood sample was drawn at a university hospital. We evaluated B-Hb and erythrocyte, thrombocyte, and leukocyte counts and their association with serum dehydroepiandrosterone sulfate (DHEAS), testosterone and IGF-I concentrations. Children with PA had higher mean blood erythrocyte count (4.74 vs. 4.64 × 10(12)/liter, P = 0.04; significant difference in girls but not in boys) and a tendency toward higher B-Hb (130 vs. 128 g/liter, P = 0.06) than their controls. No difference was observed in leukocyte or thrombocyte counts between the study groups. In linear regression models including age, sex, body mass index SD score, IGF-I, and DHEAS or testosterone, B-Hb was associated with serum DHEAS (P = 0.04), testosterone (P = 0.01), and IGF-I (P ≤ 0.003) concentrations in the entire study cohort and with IGF-I separately in girls (P ≤ 0.02). Similar models showed a significant association of blood erythrocyte count with serum IGF-I concentration (P = 0.003-0.049) but not with DHEAS or testosterone. Increased erythrocyte count in PA girls suggests that relatively small increases in serum androgen or IGF-I concentrations during adrenarche may associate with enhanced erythropoiesis.

  18. Red wine activates plasma membrane redox system in human erythrocytes.

    Science.gov (United States)

    Tedesco, Idolo; Moccia, Stefania; Volpe, Silvestro; Alfieri, Giovanna; Strollo, Daniela; Bilotto, Stefania; Spagnuolo, Carmela; Di Renzo, Massimo; Aquino, Rita P; Russo, Gian Luigi

    2016-01-01

    In the present study, we report that polyphenols present in red wine obtained by a controlled microvinification process are able to protect human erythrocytes from oxidative stress and to activate Plasma Membrane Redox System (PMRS). Human plasma obtained from healthy subjects was incubated in the presence of whole red wine at a concentration corresponding to 9.13-73 μg/ml gallic acid equivalents to verify the capacity to protect against hypochlorous acid (HOCl)-induced plasma oxidation and to minimize chloramine formation. Red wine reduced hemolysis and chloramine formation induced by HOCl of 40 and 35%, respectively. PMRS present on human erythrocytes transfers electrons from intracellular molecules to extracellular electron acceptors. We demonstrated that whole red wine activated PMRS activity in human erythrocytes isolated from donors in a dose-dependent manner with a maximum at about 70-100 μg/ml gallic acid equivalents. We also showed that red wine increased glutathione (GSH) levels and erythrocytic antioxidant capacity, measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) quenching assay. Furthermore, we reported that GSH played a crucial role in regulating PMRS activity in erythrocytes. In fact, the effect of iodoacetamide, an alkylating agent that induces depletion of intracellular GSH, was completely counteracted by red wine. Bioactive compounds present in red wine, such as gallic acid, resveratrol, catechin, and quercetin were unable to activate PMRS when tested at the concentrations normally present in aged red wines. On the contrary, the increase of PMRS activity was associated with the anthocyanin fraction, suggesting the capacity of this class of compounds to positively modulate PMRS enzymatic activity.

  19. [Effect of congrong powder preparation on erythrocyte parameter and index of blood rheology in rats].

    Science.gov (United States)

    Liu, Zhengran; Zhang, Dong; Wu, Haijun; Li, Yueling; Chen, Shiping; Yang, Yumei

    2010-11-01

    To observe the effect of Congrong powder preparation on erythrocyte parameter and the index of blood rheology in healthy rats. The 50 rats were randomly divided into 5 groups ( physiological saline group, testosterone propionate group, large-dose administered group, moderate-dose administered group, small-dose administered group). Blood were taken to determine erythrocyte parameter and the index of blood rheology. Congrong powder preparation had no effect on erythrocyte parameter. There was an increase in whole blood viscosity, whole blood reduction viscosity, and in the erythrocyte rigidity index in the large-dose administered group. Congrong powder can influence deformability and some related characters of erythrocytes.

  20. Enhanced bilirubin binding to different mammalian erythrocytes in the presence of magnesium ions

    OpenAIRE

    Ali, M. K.; Siddiqui, M.U; Tayyab, S.

    2001-01-01

    Effect of magnesium ions on the binding of bilirubin to erythrocytes of different mammalian species, namely, human, buffalo, goat and sheep was studied. Increase in the concentration of magnesium ions led to a gradual increase in the erythrocyte-bound bilirubin in both human and buffalo erythrocytes whereas in sheep and goat erythrocytes, the pronounced increase was found beyond 2.0 and 2.7 mM MgCl2 concentrations respectively. Percentage increase in erythrocyte-bound bilirubin was found high...

  1. Determination of glucose metabolites in stored erythrocytes and in erythrocytes from patients with thalassemia by analytical isotachophoresis.

    Science.gov (United States)

    Kuçi, Zyrafete; Hins, Jürgen; Kuçi, Selim; Renner, Susanne; Flottmann, Dirk; Bruchelt, Gernot

    2006-11-30

    Glycolysis is for some cells, such as erythrocytes, neutrophil granulocytes and many cancer cells, the only or most important source of energy (ATP) production. Based on previous studies we developed an isotachophoretic (ITP) method which allows, in principle, the simultaneous determination of all metabolites of glycolysis. Since glucose metabolites are small anions, mobility of some of them may overlap in isotachophoresis and, therefore, partial mixed zones are generated. By variation of the leading/terminating system, however, it is possible to separate the compounds of interest. In this communication, we describe a method for analysis of glucose metabolites in erythrocytes from healthy donors during storage in blood bags, and from patients with thalassemia, with special respect to intracellular 2,3 bisphosphoglycerate, lactate and ATP/ADP. The well known characteristic changes of glycolysis in erythrocytes during blood storage and in erythrocytes from thalassemia patients, which are often analysed by separate enzymatic assays, could be confirmed with this isotachophoretic procedure. The method is currently adapted for analysis of glycolysis in neutrophil granulocytes and cancer cells which requires some modifications of sample preparation and performance of the isotachophoretic analysis.

  2. Acute dark chocolate ingestion is beneficial for hemodynamics via enhancement of erythrocyte deformability in healthy humans.

    Science.gov (United States)

    Radosinska, Jana; Horvathova, Martina; Frimmel, Karel; Muchova, Jana; Vidosovicova, Maria; Vazan, Rastislav; Bernatova, Iveta

    2017-03-01

    Erythrocyte deformability is an important property of erythrocytes that considerably affects blood flow and hemodynamics. The high content of polyphenols present in dark chocolate has been reported to play a protective role in functionality of erythrocytes. We hypothesized that chocolate might influence erythrocytes not only after repeated chronic intake, but also immediately after its ingestion. Thus, we determined the acute effect of dark chocolate and milk (with lower content of biologically active substances) chocolate intake on erythrocyte deformability. We also focused on selected factors that may affect erythrocyte deformability, specifically nitric oxide production in erythrocytes and total antioxidant capacity of plasma. We determined posttreatment changes in the mentioned parameters 2hours after consumption of chocolate compared with their levels before consumption of chocolate. In contrast to milk chocolate intake, the dark chocolate led to a significantly higher increase in erythrocyte deformability. Nitric oxide production in erythrocytes was not changed after dark chocolate intake, but significantly decreased after milk chocolate. The plasma total antioxidant capacity remained unaffected after ingestion of both chocolates. We conclude that our hypothesis was confirmed. Single ingestion of dark chocolate improved erythrocyte deformability despite unchanged nitric oxide production and antioxidant capacity of plasma. Increased deformability of erythrocytes may considerably improve rheological properties of blood and thus hemodynamics in humans, resulting in better tissue oxygenation. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Attempts to validate a possible predictive animal model for human erythrocyte G-6-PD deficiency

    Energy Technology Data Exchange (ETDEWEB)

    Horton, H.M.; Calabrese, E.J.

    1986-01-01

    The use of Dorset sheep erythrocytes as a model for human G-6-PD deficient erythrocytes was investigated. Seven pharmaceuticals were examined for oxidant stressor effects using a liver microsomal enzyme system to generate metabolites of the drugs. The pharmaceuticals examined were salicyclic acid, dapsone, naphthalene, B-naphtol, p-aminobenzoic acid, sulfanilamide and sulfapyridine. The test compounds were incubated with Dorset sheep erythrocytes and oxidant stressor effects were measured through reduced glutathione (GSH) levels and methemaglobin formation. The response of the Dorset sheep erythrocytes to the seven agents was compared to previous studies revealing the response of human G-6-PD deficient erythrocytes to these agents. The results indicated that metabolites of the pharmaceuticals, B-naphthol, dapsone, and sulfanilamide, are oxidant stressor agents towards sheep G-6-PD deficient erythrocytes. These results agreed with studies on the response of human G-6-PD deficient erythrocytes. The metabolized naphthalene and sulfapyridine did not cause oxidant stress in the sheep erythrocytes, despite the fact that these two agents caused oxidizing effects in human G-6-PD deficient erythrocytes in previous studies. None of the non-metabolized parent compounds caused oxidant stress in the sheep erythrocytes, which agreed with the responses of human G-6-PD deficient erythrocytes.

  4. Flow cytometric determination of osmotic behaviour of animal erythrocytes toward their engineering for drug delivery

    Directory of Open Access Journals (Sweden)

    Kostić Ivana T.

    2015-01-01

    Full Text Available Despite the fact that the methods based on the osmotic properties of the cells are the most widely used for loading of drugs in human and animal erythrocytes, data related to the osmotic properties of erythrocytes derived from animal blood are scarce. This work was performed with an aim to investigate the possibility of use the flow cytometry as a tool for determination the osmotic behaviour of porcine and bovine erythrocytes, and thus facilitate the engineering of erythrocytes from animal blood to be drug carriers. The method of flow cytometry successfully provided the information about bovine and porcine erythrocyte osmotic fragility, and made the initial steps in assessment of erythrocyte shape in a large number of erythrocytes. Although this method is not able to confirm the swelling of pig erythrocytes, it indicated to the differences in pig erythrocytes that had basic hematological parameters inside and outside the reference values. In order to apply/use the porcine and bovine erythrocytes as drug carriers, the method of flow cytometry, confirming the presence of osmotically different fractions of red blood cells, indicated that various amounts of the encapsulated drug in porcine and bovine erythrocytes can be expected.

  5. Aspectos estruturais da membrana eritrocitária Structural aspects of the erythrocyte membrane

    Directory of Open Access Journals (Sweden)

    Priscila Murador

    2007-06-01

    . With its high sialic acid content, GPA is the main contributor to the net negative cell-surface charge and is thus critical for minimizing cell-cell interactions and preventing red cell aggregation. Glycophorin C (GPC is the receptor for PfEBP-2 (baebl, EBA-140, the newly identified erythrocyte binding ligand of Plasmodium falciparum. The ternary complex of spectrin, actin and 4.1R defines the nodes of the erythrocyte membrane skeletal network, and is inseparable from membrane stability when under mechanical stress. This erythrocyte membrane review is important for a better understanding of transfusion reactions, where the antibody formation against high prevalence antigens makes compatible transfusions difficult. The study of antigen diversity and biochemical characterization of different proteins will contribute to healthcare, as well as diagnosis, development of technology such as monoclonal antibody production and the therapeutic conduct of many diseases.

  6. Genetic Evidence for Erythrocyte Receptor Glycophorin B Expression Levels Defining a Dominant Plasmodium falciparum Invasion Pathway into Human Erythrocytes

    Science.gov (United States)

    Dankwa, Selasi; Chaand, Mudit; Kanjee, Usheer; Jiang, Rays H. Y.; Nobre, Luis V.; Goldberg, Jonathan M.; Bei, Amy K.; Moechtar, Mischka A.; Grüring, Christof; Ahouidi, Ambroise D.; Ndiaye, Daouda; Dieye, Tandakha N.; Mboup, Souleymane; Weekes, Michael P.

    2017-01-01

    ABSTRACT Plasmodium falciparum, the parasite that causes the deadliest form of malaria, has evolved multiple proteins known as invasion ligands that bind to specific erythrocyte receptors to facilitate invasion of human erythrocytes. The EBA-175/glycophorin A (GPA) and Rh5/basigin ligand-receptor interactions, referred to as invasion pathways, have been the subject of intense study. In this study, we focused on the less-characterized sialic acid-containing receptors glycophorin B (GPB) and glycophorin C (GPC). Through bioinformatic analysis, we identified extensive variation in glycophorin B (GYPB) transcript levels in individuals from Benin, suggesting selection from malaria pressure. To elucidate the importance of the GPB and GPC receptors relative to the well-described EBA-175/GPA invasion pathway, we used an ex vivo erythrocyte culture system to decrease expression of GPA, GPB, or GPC via lentiviral short hairpin RNA transduction of erythroid progenitor cells, with global surface proteomic profiling. We assessed the efficiency of parasite invasion into knockdown cells using a panel of wild-type P. falciparum laboratory strains and invasion ligand knockout lines, as well as P. falciparum Senegalese clinical isolates and a short-term-culture-adapted strain. For this, we optimized an invasion assay suitable for use with small numbers of erythrocytes. We found that all laboratory strains and the majority of field strains tested were dependent on GPB expression level for invasion. The collective data suggest that the GPA and GPB receptors are of greater importance than the GPC receptor, supporting a hierarchy of erythrocyte receptor usage in P. falciparum. PMID:28760933

  7. Accumulation by Conservation

    NARCIS (Netherlands)

    Büscher, Bram; Fletcher, Robert

    2015-01-01

    Following the financial crisis and its aftermath, it is clear that the inherent contradictions of capitalist accumulation have become even more intense and plunged the global economy into unprecedented turmoil and urgency. Governments, business leaders and other elite agents are frantically

  8. Accumulation by Conservation

    NARCIS (Netherlands)

    Büscher, Bram; Fletcher, Robert

    2014-01-01

    Following the financial crisis and its aftermath, it is clear that the inherent contradictions of capitalist accumulation have become even more intense and plunged the global economy into unprecedented turmoil and urgency. Governments, business leaders and other elite agents are frantically

  9. Segregation into separate rouleaux of erythrocytes from different species. Evidence against the agglomerin hypothesis of rouleaux formation.

    OpenAIRE

    Forsdyke, D R; Ford, P. M.

    1983-01-01

    Erythrocytes from one species were labelled with fluorescein isothiocyanate and mixed with unlabelled erythrocytes from another species. Albumin polymers were added to generate rouleaux. The species of origin of erythrocytes in rouleaux was determined by fluorescence microscopy. Erythrocytes from different species segregated into independent rouleaux. However, fluorescent and non-fluorescent erythrocytes from one individual were mixed randomly in rouleaux. These results confirm, using a novel...

  10. [Nonspecific effect of morphine on the erythrocyte membrane].

    Science.gov (United States)

    Kuznetsov, P E; Zlobin, V A; Nazarov, G V; Kuznetsova, N B; Rogacheva, S M; Gracheva, A A

    2004-01-01

    The effect of low morphine concentrations on the plasmatic membranes of erythrocytes without opiate receptors was investigated. It was shown that the ATPase activity and hemolytic stability of erythrocytes, which characterize the state of cell membranes and the mobility of the near-membrane water phase, depend on the concentration of morphine, and this dependence is wave-like. The nonmonotonous dependence of the biological response was suggested to be due to changes in the structure of water hydrogen links near the membrane surface, induced by opiate molecules. The hypothesis was confirmed by the results of studies of morphine water solutions using the methods of fluorescent probe and light scattering. It was found that the intensity of light scattering by water and the mobility of its molecules considerably increase in the presence of strictly specified concentrations of morphine.

  11. Quantitative evaluation of respiration induced metabolic oscillations in erythrocytes

    DEFF Research Database (Denmark)

    Hald, Bjørn; Madsen, Mads F; Danø, Sune

    2009-01-01

    solely by steady state consideration. The metabolic system exhibits a broad distribution of time scales. Relaxations of modes with hemoglobin and Mg(2+) binding reactions are very fast, while modes involving glycolytic, membrane transport and 2,3-BPG shunt reactions are much slower. Incomplete slow mode......The changes in the partial pressures of oxygen and carbon dioxide (P(O(2)) and P(CO(2))) during blood circulation alter erythrocyte metabolism, hereby causing flux changes between oxygenated and deoxygenated blood. In the study we have modeled this effect by extending the comprehensive kinetic...... model by Mulquiney and Kuchel [P.J. Mulquiney, and P.W. Kuchel. Model of 2,3-bisphosphoglycerate metabolism in the human erythrocyte based on detailed enzyme kinetic equations: equations and parameter refinement, Biochem. J. 1999, 342, 581-596.] with a kinetic model of hemoglobin oxy...

  12. Sickle discocytes form more rouleaux in vitro than normal erythrocytes.

    Science.gov (United States)

    Obiefuna, P C; Photiades, D P

    1990-06-01

    Rouleaux formation of washed erythrocytes was studied in 32 normal (HbAA) individuals and 30 sickle cell anaemia (HbSS) patients. Washed red cells were suspended in their plasma and rouleaux formation visualized with the aid of an inverted microscope connected to a video camera-monitor unit. Aggregation rate was studied by visual particle counting. Washed sickle discocytes showed rouleaux formation three times as high as normal cells. Red cells were also suspended in buffered Ringer solution containing dextran (a rouleaux inducer). Again, washed erythrocytes from sicklers were about 3 times more aggregable than normal cells at all pH values studied. Increased acidity appeared to aggravate rouleaux formation in both Hb genotypes. We also found plasma fibrinogen concentration in sicklers to be about twice as high as that of normals. High rouleaux formation in sicklers could be attributed not only to fibrinogen and other plasma factors but also to cellular factors.

  13. Human erythrocytes as nanoparticle carriers for magnetic particle imaging

    Energy Technology Data Exchange (ETDEWEB)

    Markov, D E; Boeve, H [Philips Research Europe, High Tech Campus 4, 5656 AE Eindhoven (Netherlands); Gleich, B; Borgert, J [Philips Research Europe, Sector Medical Imaging Systems, Roentgenstrasse 24-26, 22335 Hamburg (Germany); Antonelli, A; Sfara, C; Magnani, M, E-mail: hans.boeve@philips.co, E-mail: bernhard.gleich@philips.co, E-mail: joern.borgert@philips.co, E-mail: antonella.antonelli@uniurb.i, E-mail: carla.sfara@uniurb.i, E-mail: mauro.magnani@uniurb.i [Department of Biomolecular Sciences, University of Urbino, Via Saffi 2, Urbino, 61029 (Italy)

    2010-11-07

    The potential of red blood cells (RBCs) loaded with iron oxide nanoparticles as a tracer material for magnetic particle imaging (MPI) has been investigated. MPI is an emerging, quantitative medical imaging modality which holds promise in terms of sensitivity in combination with spatial and temporal resolution. Steady-state and dynamic magnetization measurements, supported by semi-empirical modeling, were employed to analyze the MPI signal generation using RBCs as novel biomimetic constructs. Since the superparamagnetic iron oxide (SPIO) bulk material that is used in this study contains nanoparticles with different sizes, it is suggested that during the RBC loading procedure, a preferential entrapment of nanoparticles with hydrodynamic diameter {<=}60 nm occurs by size-selection through the erythrocyte membrane pores. This affects the MPI signal of an erythrocyte-based tracer, compared to bulk. The reduced signal is counterbalanced by a higher in vivo stability of the SPIO-loaded RBCs constructs for MPI applications.

  14. Biochemically altered human erythrocytes as a carrier for targeted delivery of primaquine: an in vitro study.

    Science.gov (United States)

    Alanazi, Fars K; Harisa, Gamal El-Din I; Maqboul, Ahmad; Abdel-Hamid, Magdi; Neau, Steven H; Alsarra, Ibrahim A

    2011-04-01

    The aim of this study was to investigate human erythrocytes as a carrier for targeted drug delivery of primaquine (PQ). The process of PQ loading in human erythrocytes, as well as the effect of PQ loading on the oxidative status of erythrocytes, was also studied. At PQ concentrations of 2, 4, 6, and 8 mg/mL and an incubation time of 2 h, the ratios of the concentrations of PQ entrapped in erythrocytes to that in the incubation medium were 0.515, 0.688, 0.697 and 0.788, respectively. The maximal decline of erythrocyte reduced glutathione content was observed at 8 mg/mL of PQ compared with native erythrocytes p erythrocytes was increased in comparison with unloaded cells. Electron microscopy revealed spherocyte formation with PQ carrier erythrocytes. PQ-loaded cells showed sustained drug release over a 48 h period. Erythrocytes were loaded with PQ successfully, but there were some biochemical as well as physiological changes that resulted from the effect of PQ on the oxidative status of drug-loaded erythrocytes. These changes may result in favorable targeting of PQ-loaded cells to reticulo-endothelial organs. The relative impact of these changes remains to be explored in ongoing animal studies.

  15. The reference range of serum, plasma and erythrocyte magnesium

    Directory of Open Access Journals (Sweden)

    Suzanna Immanuel

    2006-12-01

    Full Text Available The interest in the clinical importance of serum magnesium level has just recently begun with the analysis and findings of abnormal magnesium level in cardiovascular, metabolic and neuromuscular disorder. Although the serum level does not reflect the body magnesium level, but currently, only serum magnesium determination is widely used. Erythrocyte magnesium is considered more sensitive than serum magnesium as it reflects intracellular magnesium status. According to NCCLS (National Committee for Clinical Laboratory Standards every laboratory is recommended to have its own reference range for the tests it performs, including magnesium determination. The reference range obtained is appropriate for the population and affected by the method and technique. This study aimed to find the reference range of serum and plasma magnesium and also intracellular magnesium i.e. erythrocyte magnesium by direct method, and compare the results of serum and plasma magnesium. Blood was taken from 114-blood donor from Unit Transfusi Darah Daerah (UTDD Budhyarto Palang Merah Indonesia (PMI DKI Jakarta, consisted of 57 male and 57 female, aged 17 – 65 years, clinically healthy according to PMI donor criteria. Blood was taken from blood set, collected into 4 ml vacuum tube without anticoagulant for serum magnesium determination and 3 ml vacuum tube with lithium heparin for determination of erythrocyte and plasma magnesium Determination of magnesium level was performed with clinical chemistry auto analyzer Hitachi 912 by Xylidil Blue method colorimetrically. This study showed no significant difference between serum and heparinized plasma extra cellular magnesium. The reference range for serum or plasma magnesium was 1.30 – 2.00 mEq/L and for erythrocyte magnesium was 4.46 - 7.10 mEq/L. (Med J Indones 2006; 15:229-35Keywords: Reference range, extracellular magnesium, intracellular magnesium

  16. Purification and properties of enolase of human erythrocytes

    NARCIS (Netherlands)

    Hoorn, R.K.J.; Flikweert, J.P.; Staal, Gerard E.J.

    1974-01-01

    1. 1. Human erythrocyte enolase (2-phospho-D-glycerate hydrolyase, EC 4.2.1.11) was purified I000-fold. 2. 2. The pH-optimum was at pH 6.5. The molecular weight, estimated by gel filtration, was found to be 95,000 ± 5,000. 3. 3. Electrophoresis on agar-agarose at pH 8.5 and 6.4 showed only one

  17. Purification and properties of enolase of human erythrocytes

    NARCIS (Netherlands)

    Hoorn, R.K.J.; Flikweert, J.P.; Staal, Gerard E.J.

    1. 1. Human erythrocyte enolase (2-phospho-D-glycerate hydrolyase, EC 4.2.1.11) was purified I000-fold. 2. 2. The pH-optimum was at pH 6.5. The molecular weight, estimated by gel filtration, was found to be 95,000 ± 5,000. 3. 3. Electrophoresis on agar-agarose at pH 8.5 and 6.4 showed only one

  18. Erythrocyte glucose-6-phosphate dehydrogenase from Brazilian opossum Didelphis marsupialis

    Directory of Open Access Journals (Sweden)

    Barretto O.C. de O.

    2006-01-01

    Full Text Available In a comparative study of erythrocyte metabolism of vertebrates, the specific activity of glucose-6-phosphate dehydrogenase (G6PD of the Brazilian opossum Didelphis marsupialis in a hemolysate was shown to be high, 207 ± 38 IU g-1 Hb-1 min-1 at 37ºC, compared to the human erythrocyte activity of 12 ± 2 IU g-1 Hb-1 min-1 at 37ºC. The apparent high specific activity of the mixture led us to investigate the physicochemical properties of the opossum enzyme. We report that reduced glutathione (GSH in the erythrocytes was only 50% higher than in human erythrocytes, a value lower than expected from the high G6PD activity since GSH is maintained in a reduced state by G6PD activity. The molecular mass, determined by G-200 Sephadex column chromatography at pH 8.0, was 265 kDa, which is essentially the same as that of human G6PD (260 kDa. The Michaelis-Menten constants (Km: 55 µM for glucose-6-phosphate and nicotinamide adenine dinucleotide phosphate (Km: 3.3 µM were similar to those of the human enzyme (Km: 50-70 and Km: 2.9-4.4, respectively. A 450-fold purification of the opossum enzyme was achieved and the specific activity of the purified enzyme, 90 IU/mg protein, was actually lower than the 150 IU/mg protein observed for human G6PD. We conclude that G6PD after purification from the hemolysate of D. marsupialis does not have a high specific activity. Thus, it is quite probable that the red cell hyperactivity reported may be explained by increased synthesis of G6PD molecules per unit of hemoglobin or to reduced inactivation in the RBC hemolysate.

  19. Influence of calcium blockers on the SPR of erythrocytes

    Science.gov (United States)

    Shynkarenko, Olena V.; Tril, Orest; Wojnarowska, Renata; Prohorenko, Sergiy; Shergii, E. M.

    2017-01-01

    One of the promising areas of research is the impact of calcium channel blockers (CB) of biological fluids. This paper shows that the CB impact on a biological fluid can be efficiently combine with the surface plasmon resonance (SPR). It is shown that the addition of CB at the SPR measurements affect the stability of membranes and acts differently on the kinetics of erythrocytes ligament in the different groups of people.

  20. Observation on PI (Π) based dimensions of the erythrocyte

    African Journals Online (AJOL)

    This paper reports data, which suggests that the relative dimensions of the blood erythrocyte appear to be approximate powers of the number pi (Π = 3.14). The estimated dimensions are: center thickness = 0.81μm; rim thickness = 2.58μm; diameter = 7.82μm; circumference = 24.57μm. These yielded simple ratios of: 1.00: ...

  1. Effects of Aspirin on Rheological Properties of Erythrocytes In Vitro

    OpenAIRE

    Elblbesy, Mohamed A.; Hereba, Abdel Rahman M.; Shawki, Mamdouh M.

    2012-01-01

    Aspirin is of proven value as an antithrombotic drug. In unstable angina it reduces the risk of death and myocardial infarction by half. Most studies on the mechanism of action of aspirin have concentrated on the effect of aspirin on platelets. In the present study we have tried to prove that there is another biophysical mechanism of aspirin, and that is through the effect of aspirin on erythrocytes. In this study ten blood samples were incubated with aspirin at different concentrations. The ...

  2. Stability of erythrocyte suspensions layered on stationary and flowing liquids

    Science.gov (United States)

    Omenyi, S. N.; Rhodes, P. H.; Snyder, R. S.

    1982-01-01

    The apparent stability of erythrocyte suspensions layered on stationary and flowing Ficoll solutions was studied considering the effects of particle concentration, type and size, and the different flow rates of the particle suspensions and chamber liquid. The data from the flowing system were empirically fitted and, when extrapolated to zero chamber liquid flow rate, gave values comparable to the data from the stationary system, thus confirming the validity of the data and our approach to obtain that data.

  3. [Ratio of erythrocyte and plasma in massive blood transfusion].

    Science.gov (United States)

    Wen, Xian-Hui; Liu, Feng-Xia; Zhang, Jun-Hua; Gui, Rong

    2014-06-01

    This study was purposed to explore the suitable ratio between fresh frozen plasma and erythrocyte by retrospective analysis of coagulation in patients with massive blood transfusion. The clinical data of 151 cases with massive blood transfusion from January 2011 to January 2013 were analyzed retrospectively. According to coagulation, patients were divided into coagulation normal group (138 cases) and coagulation dysfunction group (13 cases). Based on the ratio of 1:1 of fresh frozen plasma and erythrocyte, the patients were divided into high plasma group(2:1), medium plasma group (1:1) and low plasma (blood transfusion. The results showed that prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT) were prolonged, fibrinogen (FIB) level decreased significantly (all P blood transfusion 24 h; the high plasma and the medium plasma group of coagulation normal group had no significant changes in coagulation (P > 0.05); prothrombin time, activated partial thromboplastin time, thrombin time and fibrinogen level in the medium plasma and low plasma subgroup of coagulation dysfunction group after massive transfusion was still in abnormal levels (P > 0.05), coagulation function in high plasma subgroup was improved significantly (P blood transfusion, the ratio between fresh frozen plasma and erythrocyte is recommended to be 2:1 in patients of coagulation dysfunction in order to improve the patient's coagulation function and to reduce the incidence of adverse event, the ratio of fresh frozen plasma to erythrocyte is recommended to be 1:1 in patients with normal coagulation so as to reduce the dilutional coagulopathy and hypervolemia of blood.

  4. Piperlongumine-Induced Phosphatidylserine Translocation in the Erythrocyte Membrane

    Directory of Open Access Journals (Sweden)

    Rosi Bissinger

    2014-10-01

    Full Text Available Background: Piperlongumine, a component of Piper longum fruit, is considered as a treatment for malignancy. It is effective by inducing apoptosis. Mechanisms involved in the apoptotic action of piperlongumine include oxidative stress and activation of p38 kinase. In analogy to apoptosis of nucleated cells, erythrocytes may undergo eryptosis, the suicidal death of erythrocytes characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine-exposure at the erythrocyte surface. Signaling involved in eryptosis include increase of cytosolic Ca2+-activity ([Ca2+]i, formation of ceramide, oxidative stress and activation of p38 kinase. Methods: Cell volume was estimated from forward scatter, phosphatidylserine-exposure from annexin V binding, [Ca2+]i from Fluo3 fluorescence, reactive oxygen species from 2',7'-dichlorodihydrofluorescein-diacetate fluorescence, and ceramide abundance from binding of fluorescent antibodies in flow cytometry. Results: A 48 h exposure to piperlongumine (30 µM was followed by significant decrease of forward scatter and increase of annexin-V-binding. Piperlongumine did not significantly modify [Ca2+]i and the effect was not dependent on presence of extracellular Ca2+. Piperlongumine significantly increased ROS formation and ceramide abundance. Conclusions: Piperlongumine triggers cell membrane scrambling, an effect independent from entry of extracellular Ca2+ but at least partially due to ROS and ceramide formation.

  5. Erythrocyte oxidative stress markers in children with sickle cell disease

    Directory of Open Access Journals (Sweden)

    Priscila Bacarin Hermann

    2016-08-01

    Full Text Available Abstract Objective To determine eight parameters of oxidative stress markers in erythrocytes from children with sickle cell disease and compare with the same parameters in erythrocytes from healthy children, since oxidative stress plays an important role in the pathophysiology of sickle cell disease and because this disease is a serious public health problem in many countries. Methods Blood samples were obtained from 45 children with sickle cell disease (21 males and 24 females with a mean age of 9 years; range: 3–13 years and 280 blood samples were obtained from children without hemoglobinopathies (137 males and 143 females with a mean age of 10 years; range: 8–11 years, as a control group. All blood samples were analyzed for methemoglobin, reduced glutathione, thiobarbituric acid reactive substances, percentage of hemolysis, reactive oxygen species, and activity of the enzymes glucose 6-phosphate dehydrogenase, superoxide dismutase, and catalase. Data were analyzed using Student's t-test and were expressed as the mean ± standard deviation. A p-value of <0.05 was considered significant. Results Significant differences were observed between children with sickle cell disease and the control group for the parameters methemoglobin, thiobarbituric acid reactive substances, hemolysis, glucose 6-phosphate dehydrogenase activity, and reactive oxygen species, with higher levels in the patients than in the controls. Conclusions Oxidative stress parameters in children's erythrocytes were determined using simple laboratory methods with small volumes of blood; these biomarkers can be useful to evaluate disease progression and outcomes in patients.

  6. Transformation of zearalenone and zearalenol by rat erythrocytes.

    Science.gov (United States)

    Chang, W M; Lin, J K

    1984-11-01

    The interconversion of zearalenone and zearalenol by rat erythrocytes in vitro has been investigated. The major metabolite obtained by incubating zearalenone with erythrocytes or whole blood from Sprague-Dawley rats was alpha-zearalenol. beta-Zearalenol was also formed but at levels several times lower than those of alpha-zearalenol. In the cell-free haemolysate NADPH was much more effective than NADH as a co-factor in the reduction of zearalenone. The maximal transformation of zearalenone to zearalenol by haemolysates occurred at pH 8.0. Both NAD+ and NADP+ were effective as co-factors in the oxidation of alpha-zearalenol to zearalenone. However, only NADP+ was effective as a co-factor in the oxidation of beta-zearalenol. Conversion of alpha-zearalenol and beta-zearalenol to the corresponding epimer was observed in both erythrocyte suspensions and in cell-free haemolysates. The significance of these findings to the metabolism of zearalenone in vivo is discussed.

  7. Rapamycin alleviates oxidative stress-induced damage in rat erythrocytes.

    Science.gov (United States)

    Singh, Abhishek Kumar; Singh, Sandeep; Garg, Geetika; Rizvi, Syed Ibrahim

    2016-10-01

    An imbalanced cellular redox system promotes the production of reactive oxygen species (ROS) that may lead to oxidative stress-mediated cell death. Erythrocytes are the best-studied model of antioxidant defense mechanism. The present study was undertaken to investigate the effect of the immunosuppressant drug rapamycin, an inducer of autophagy, on redox balance of erythrocytes and blood plasma of oxidatively challenged rats. Male Wistar rats were oxidatively challenged with HgCl2 (5 mg/kg body mass (b.m.)). A significant (p membrane redox system (PMRS), intracellular Ca2+ influx, lipid peroxidation (LPO), osmotic fragility, plasma protein carbonyl (PCO) content, and plasma advanced oxidation protein products (AOPP) and simultaneously significant reduction in glutathione (GSH) level and ferric reducing ability of plasma (FRAP) were observed in rats exposed to HgCl2. Furthermore, rapamycin (0.5 mg/kg b.m.) provided significant protection against HgCl2-induced alterations in rat erythrocytes and plasma by reducing ROS production, PMRS activity, intracellular Ca2+ influx, LPO, osmotic fragility, PCO content, and AOPP and also restored the level of antioxidant GSH and FRAP. Our observations provide evidence that rapamycin improves redox status and attenuates oxidative stress in oxidatively challenged rats. Our data also demonstrate that rapamycin is a comparatively safe immunosuppressant drug.

  8. Drug-loaded erythrocytes: on the road toward marketing approval

    Science.gov (United States)

    Bourgeaux, Vanessa; Lanao, José M; Bax, Bridget E; Godfrin, Yann

    2016-01-01

    Erythrocyte drug encapsulation is one of the most promising therapeutic alternative approaches for the administration of toxic or rapidly cleared drugs. Drug-loaded erythrocytes can operate through one of the three main mechanisms of action: extension of circulation half-life (bioreactor), slow drug release, or specific organ targeting. Although the clinical development of erythrocyte carriers is confronted with regulatory and development process challenges, industrial development is expanding. The manufacture of this type of product can be either centralized or bedside based, and different procedures are employed for the encapsulation of therapeutic agents. The major challenges for successful industrialization include production scalability, process validation, and quality control of the released therapeutic agents. Advantages and drawbacks of the different manufacturing processes as well as success key points of clinical development are discussed. Several entrapment technologies based on osmotic methods have been industrialized. Companies have already achieved many of the critical clinical stages, thus providing the opportunity in the future to cover a wide range of diseases for which effective therapies are not currently available. PMID:26929599

  9. Antiproton Accumulator (AA)

    CERN Multimedia

    Photographic Service

    1980-01-01

    The AA in its final stage of construction, before it disappeared from view under concrete shielding. Antiprotons were first injected, stochastically cooled and accumulated in July 1980. From 1981 on, the AA provided antiprotons for collisions with protons, first in the ISR, then in the SPS Collider. From 1983 on, it also sent antiprotons, via the PS, to the Low-Energy Antiproton Ring (LEAR). The AA was dismantled in 1997 and shipped to Japan.

  10. [Changes of erythrocyte deformability in rats acclimatized to hypoxia and its molemechanism].

    Science.gov (United States)

    Nie, Hong-Jing; Tian, Yun-Mei; Zhang, Dong-Xiang; Wang, Hai

    2011-02-01

    To observe the changes of erythrocyte deformability in rats acclimatized to hypoxia and its molemechanism. Male rats were randomly divided into three groups (n = 10): normal control group, acute hypoxia group and hypoxia acclimatization group. Animals were exposed to hypoxia for 0, 1, 28 d, blooded from their hearts after anaesthetized, respectively. Erythrocyte deformability, membrane fluidity, cholesterin and total lipid, lipid components of erythrocyte membrane, erythrocyte membrane ATPase and the concentrations of Na+ and Ca2+ were measured respectively. The two-dimensional electrophoresis maps of the rats erythrocyte membrane protein were achieved. The different protein spots were founded by image master 2D elite and identified by mass spectrum. (1) In acute hypoxia group, the deformability, membrane fluidity, the content of membrane cholesterin and total lipid were declined. The content of phosphatidylserines (PS), sphingomyelin (SM) in erythrocyte membrane lipids were increased, phosphatidylcholine (PC) reduced. The activity of ATP enzymes reduced and the concentration of Na+ and Ca2+ in erythrocyte increased. The two-dimensional electrophoresis maps of the rats erythrocyte membrane protein were achieved. Four of the seven protein spots selected increased and three of them showed no change. (2) In hypoxia acclimatization group, the deformability, membrane fluidity, the content of membrane cholesterin and total lipid were increased than those in acute hypoxia group, similar to normal group. The content of PS, SM in erythrocyte membrane lipids were reduced, PC increased. The activity of ATP enzymes induced and the concentration of Na+ and Ca2+ in erythrocyte increased after hypoxia acclimatization. Four of those protein spots mentioned increase and three declined after hypoxia acclimatization. They were respectively proved by mass spectrum to be alexin binding protein, aquaporin chip, membrane inhibitor reactive lysis, phospholipids scramblase, glucose

  11. Phospholipid metabolism of serine in Plasmodium-infected erythrocytes involves phosphatidylserine and direct serine decarboxylation.

    Science.gov (United States)

    Elabbadi, N; Ancelin, M L; Vial, H J

    1997-01-01

    Erythrocytes infected with Plasmodium falciparum or Plasmodium knowlesi efficiently incorporated radioactive serine into phosphatidylserine (PtdSer), phosphatidylethanolamine (PtdEtn) and phosphatidylcholine (PtdCho). Serine was also metabolized into ethanolamine (Etn) and phosphorylethanolamine (P-Etn) via direct serine decarboxylation; this is a major phenomenon since together these metabolites represent 60% of total radioactive water-soluble metabolites. They were identified by reverse-phase HPLC and two TLC-type analyses and confirmed by alkaline phosphatase treatment, which depleted the radioactive P-Etn peak completely with a concomitant increase in that of Etn. In the presence of 5 microM labelled serine, radioactivity appeared in Etn and P-Etn after a 25 min lag period, and isotopic equilibrium was reached at 40 and 95 min respectively. There was a similar lag period for PtdEtn formation, which accumulated steadily for at least 180 min. Incorporation of serine into phospholipids and water-soluble metabolites increased in the presence of up to 500 microM external serine. An apparent plateau was then reached for all metabolites except intracellular serine and Etn. Exogenous Etn (at 20 microM) induced a concomitant dramatic decrease in serine incorporation into P-Etn and all phospholipids, but not into Etn. Increasing exogenous serine to 100 microM decreased the incorporation of radioactive Etn into PtdEtn by only 30%, and the PtdCho level was not affected. 2-Hydroxyethylhydrazine significantly decreased serine incorporation into P-Etn and PtdEtn, whereas Etn was accumulated. No concomitant inhibition of PtdSer or PtdCho labelling from serine occurred, even when PtdEtn formation was decreased by 95%. This indicates that the PtdEtn pool derived from direct serine decarboxylation differed from that derived from PtdSer decarboxylation, and the latter appeared to be preferentially used for PtdCho biosynthesis. Hydroxylamine also inhibited phosphorylation of serine

  12. Selenium accumulation by plants.

    Science.gov (United States)

    White, Philip J

    2016-02-01

    Selenium (Se) is an essential mineral element for animals and humans, which they acquire largely from plants. The Se concentration in edible plants is determined by the Se phytoavailability in soils. Selenium is not an essential element for plants, but excessive Se can be toxic. Thus, soil Se phytoavailability determines the ecology of plants. Most plants cannot grow on seleniferous soils. Most plants that grow on seleniferous soils accumulate plant species have evolved tolerance to Se, and commonly accumulate tissue Se concentrations >100 mg Se kg(-1) dry matter. These plants are considered to be Se accumulators. Some species can even accumulate Se concentrations of 1000-15 000 mg Se kg(-1 )dry matter and are called Se hyperaccumulators. This article provides an overview of Se uptake, translocation and metabolism in plants and highlights the possible genetic basis of differences in these between and within plant species. The review focuses initially on adaptations allowing plants to tolerate large Se concentrations in their tissues and the evolutionary origin of species that hyperaccumulate Se. It then describes the variation in tissue Se concentrations between and within angiosperm species and identifies genes encoding enzymes limiting the rates of incorporation of Se into organic compounds and chromosomal loci that might enable the development of crops with greater Se concentrations in their edible portions. Finally, it discusses transgenic approaches enabling plants to tolerate greater Se concentrations in the rhizosphere and in their tissues. The trait of Se hyperaccumulation has evolved several times in separate angiosperm clades. The ability to tolerate large tissue Se concentrations is primarily related to the ability to divert Se away from the accumulation of selenocysteine and selenomethionine, which might be incorporated into non-functional proteins, through the synthesis of less toxic Se metabilites. There is potential to breed or select crops

  13. Thrombin Cleavage of Plasmodium falciparum Erythrocyte Membrane Protein 1 Inhibits Cytoadherence.

    Science.gov (United States)

    Gillrie, Mark R; Renaux, Bernard; Russell-Goldman, Eleanor; Avril, Marion; Brazier, Andrew J; Mihara, Koichiro; Di Cera, Enrico; Milner, Danny A; Hollenberg, Morley D; Smith, Joseph D; Ho, May

    2016-09-13

    Plasmodium falciparum malaria remains one of the most deadly infections worldwide. The pathogenesis of the infection results from the sequestration of infected erythrocytes (IRBC) in vital organs, including the brain, with resulting impairment of blood flow, hypoxia, and lactic acidosis. Sequestration occurs through the adhesion of IRBC to host receptors on microvascular endothelium by Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1), a large family of variant surface antigens, each with up to seven extracellular domains that can bind to multiple host receptors. Consequently, antiadhesive therapies directed at single endothelial adhesion molecules may not be effective. In this study, we demonstrated that the serine protease thrombin, which is pivotal in the activation of the coagulation cascade, cleaved the major parasite adhesin on the surface of IRBC. As a result, adhesion under flow was dramatically reduced, and already adherent IRBC were detached. Thrombin cleavage sites were mapped to the Duffy binding-like δ1 (DBLδ1) domain and interdomains 1 and 2 in the PfEMP1 of the parasite line IT4var19. Furthermore, we observed an inverse correlation between the presence of thrombin and IRBC in cerebral malaria autopsies of children. We investigated a modified (R67A) thrombin and thrombin inhibitor, hirugen, both of which inhibit the binding of substrates to exosite I, thereby reducing its proinflammatory properties. Both approaches reduced the barrier dysfunction induced by thrombin without affecting its proteolytic activity on PfEMP1, raising the possibility that thrombin cleavage of variant PfEMP1 may be exploited as a broadly inhibitory antiadhesive therapy. Plasmodium falciparum malaria is the third leading cause of mortality due to a pathogen, with 214 million people infected and 438,000 deaths annually. The adhesion of Plasmodium falciparum-infected erythrocytes (IRBC) to microvascular endothelium is a major pathological process in severe malaria

  14. Altitude acclimatization and blood volume: effects of exogenous erythrocyte volume expansion

    DEFF Research Database (Denmark)

    Sawka, M N; Young, Jette Feveile; Rock, P B

    1996-01-01

    We studied sea-level residents during 13 days of altitude acclimatization to determine 1) altitude acclimatization effects on erythrocyte volume and plasma volume, 2) if exogenous erythrocyte volume expansion alters subsequent erythrocyte volume and plasma volume adaptations, 3) if an increased...... blood oxygen content alters erythropoietin responses during altitude acclimatization, and 4) mechanisms responsible for plasma loss at altitude. Sixteen healthy men had a series of hematologic measurements made at sea level, on the first and ninth days of altitude (4,300 m) residence, and after...... returning to sea level. Twenty-four hours before the ascent to altitude, one group received a 700-ml infusion of autologous erythrocytes (42% hematocrit), whereas the other group received only a saline infusion. Erythrocyte infusion increased erythrocyte volume by approximately 10%, whereas saline infusion...

  15. Erythrocyte copper chaperone for superoxide dismutase and superoxide dismutase as biomarkers for hepatic copper concentrations in Labrador retrievers.

    Science.gov (United States)

    Dirksen, K; Roelen, Y S; van Wolferen, M E; Kruitwagen, H S; Penning, L C; Burgener, I A; Spee, B; Fieten, H

    2016-12-01

    Hereditary hepatic copper accumulation in Labrador retrievers leads to hepatitis with fibrosis and eventually cirrhosis. The development of a non-invasive blood-based biomarker for copper status in dogs could be helpful in identifying dogs at risk and to monitor copper concentrations during treatment. In this study, two cellular copper metabolism proteins, Cu/Zn superoxide dismutase (SOD1) and its chaperone (copper chaperone for SOD1, CCS) were measured in erythrocytes and tested for association with hepatic copper concentrations in 15 Labrador retrievers with normal or increased hepatic copper concentrations. Antibodies against CCS and SOD1 were applicable for use in canine specimens. This was demonstrated by the loss of immune-reactive bands for CCS and SOD1 in siRNA treated canine bile duct epithelial cells. Erythrocyte CCS and CCS/SOD1 ratios were decreased 2.37 (P Labrador retrievers and could facilitate early diagnosis and treatment monitoring for copper-associated hepatitis in dogs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Nutrition and Reproductive Health: Sperm versus Erythrocyte Lipidomic Profile and ?-3 Intake

    OpenAIRE

    Gabriela Ruth Mendeluk; Mariano Isaac Cohen; Carla Ferreri; Chryssostomos Chatgilialoglu

    2015-01-01

    Fatty acid analyses of sperm and erythrocyte cell membrane phospholipids in idiopathic infertile patients evidenced that erythrocyte contents of EPA, DHA, omega-6–omega-3 ratio and arachidonic acid provide a mathematical correspondence for the prediction of EPA level in sperm cells. The erythrocyte lipidomic profile of patients was significantly altered, with signatures of typical Western pattern dietary habits and no fish intake. A supplementation with nutritional levels of EPA and DHA and a...

  17. Inhibition by Teriflunomide of Erythrocyte Cell Membrane Scrambling Following Energy Depletion, Oxidative Stress and Ionomycin

    National Research Council Canada - National Science Library

    Zierle, Jens; Bissinger, Rosi; Lang, Florian

    2016-01-01

    ... with translocation of phosphatidylserine to the erythrocyte surface. Triggers of cell membrane scrambling include energy depletion, oxidative stress and increase of cytosolic Ca2+ activity ([Ca2...

  18. [Density-specific distribution of erythrocytes in different types of anemia].

    Science.gov (United States)

    Shurkhina, E S; Nesterenko, V M; Kolodeĭ, S V; Tsvetaeva, N V; Ermakova, T A; Nikulina, O F; Kolosheĭnova, T I; Ataullakhanov, F I

    2009-01-01

    To study density-specific distribution of erythrocytes (DSDE) in different types of anemia. DSDE was determined in anemic patients by fractionation of the whole blood in hematocritic capillaries in the presence of mixtures of dimethyl- and dibutylphthalates with known density. Parameters are proposed which characterize DSDE changes typical for each type of anemia: mean erythrocyte density (MED)--mean density of total erythrocytic population; DSDE width (W)--a characteristic of erythrocytic population heterogeneity; light fraction of erythrocytes (LEF)--% of the cells with density less than 1.086 g/ml (hypochromic cells and reticulocytes); dense fraction of erythrocytes (DEF)--% of cells with density over 1.112 g/ml (hyperchromic cells forming as a result of erythrocyte dehydration). DSDE parameters for different types of anemia differed: reduced MED was typical for iron deficiency anemia (IDA) and paroxysmal nocturnal hemoglobinuria (PNH), increased DEF was seen in microspherocytic anemia (MSA), autoimmune hemolytic anemia (AHA), deficiency of glucose-6-phosphate dehydrogenase, increased LEF was observed in reticulocytosis in all anemia types except MSA, DSDE W was larger in MSA, AHA, PNA. DSDE is determined by proportion of erythropoiesis and sequestration of erythrocytes as well as pathological impacts leading to impairment of membrane permeability for cations and erythrocytic metabolism. Informative value of DSDE parameters makes them effective for diagnostic screening of anemias and control over course of different diseases.

  19. ATP release and extracellular nucleotidase activity in erythrocytes and coronary circulation of rainbow trout

    DEFF Research Database (Denmark)

    Jensen, Frank Bo; Agnisola, Claudio; Novak, Ivana

    2009-01-01

    The present study tested the hypothesis that rainbow trout erythrocytes release ATP upon deoxygenation, a mechanism that enables mammalian erythrocytes to produce local vasodilation. We also investigated ATP release and ectonucleotidase activity in the coronary circulation of the isolated trout...... heart. Erythrocytes suspended in an albumin-containing saline and equilibrated at physiological Pco2 showed negligible hemolysis (... in its absence, revealing the presence of ectonucleotidase activity. The induction of either a slow (minutes) or a fast (seconds) decrease in hemoglobin O2 saturation did not lead to additional ATP release. An elevation of Pco2 was also without influence on erythrocyte ATP release. In the saline...

  20. Kai 1 and Kai 2: Characterization of these dog erythrocyte antigens by monoclonal antibodies

    National Research Council Canada - National Science Library

    Jae Ho Lee; Urs Giger; Hee Young Kim

    2017-01-01

    Dog Erythrocyte Antigens (DEA) have thus far been found by sensitizing dogs with canine allogeneic blood and are clinically important regarding blood transfusion incompatibilities, but remain poorly defined...

  1. Pathomorphosis of erythrocytes in patients with acquired valvular heart diseases and under conditions of their correction.

    Science.gov (United States)

    Novitskii, V V; Ryazantseva, N V; Vecherskii, Yu Yu; Lapitskaya, O I; Stepovaya, E A

    2004-03-01

    Scanning electron microscopic study of the morphology and surface architectonics of erythrocytes in patients with acquired aortic and mitral valve diseases showed signs of morphological restructuring of the erythrocyte population. Reversibly transformed transitional red blood cells and irreversibly changed prehemolytical and degenerative erythrocytes were much more incident in these patients than in donors. The number of functionally intact biconcave discocytes notably decreased in comparison with donors. Morphological heterogeneity of the erythrocyte pool increased during the immediate period after replacement of heart valves with mechanical disc prostheses. Disorganization of the surface relief of red blood cells persisted 12-24 months after surgery.

  2. Two-Phase Accumulator

    Science.gov (United States)

    Kalb, Charles E.; Kosson, Robert L.; Alario, Joseph P.; Brown, Richard F.; Edlestein, Fred

    1990-01-01

    Two-phase accumulator maintains pressure and temperature in thermal-bus system within predetermined range during variations in heat load on system. Stores liquid and vapor ammonia. Exchanges liquid ammonia with condenser to adjust level of liquid in condenser. Prototype has capacity of 13 gallons (49 liters). Simple and highly reliable. Responds quickly, restoring pressure and temperature to proper values within minutes. Low in cost and requires little further development. Used to dispose of waste heat, such as that from electronic equipment or power-plant.

  3. Low magnesium concentration in erythrocytes of children with acute asthma.

    Science.gov (United States)

    Sedighi, Mostafa; Pourpak, Zahra; Bavarian, Behrouz; Safaralizadeh, Reza; Zare, Ahad; Moin, Mostafa

    2006-12-01

    Magnesium (Mg) is the second most abundant intracellular cation and is involved in numerous physiological functions, including protein folding, intracellular signaling and enzyme catalysis. It has been shown that magnesium deficiency exacerbates pulmonary airways hyper reactivity. Several studies suggest that magnesium level has no effect on asthma but others had shown a contributory effect. Because of its intracellular abundance the aim of this study was to determine if there was any difference in plasma and intracellular Mg concentrations of children with acute asthma compared to non asthmatic children. Twenty nine patients with acute asthma aged 2 to11 years admitted to the emergency department of hospital and 37 non asthmatic children with the same age were included in our study. 0.5 mL of heparinized whole blood samples of patients who were meeting inclusion criteria at the onset of admission with bronchoconstriction and before using any medication was drawn and it was immediately sent to the laboratory. Plasma and erythrocytes were separated and stored at -20C and later their Mg levels were quantified with atomic absorption spectrophotometry method. The average plasma and intracellular magnesium levels in patients were (0.79 +/- 0.098 mmol/L) and (1.17 +/- 0.27 mmol/L) respectively. Results of 37 non asthmatic persons [plasma (0.85 +/- 0.1 mmol/L ) and erythrocytes (1.33 +/- 0.21 mmol/L)] showed that there was no significant difference between plasma Mg levels in two groups (p 0.06) but intracellular magnesium level was significantly lower (p 0.03) in patients group. These results indicate that intracellular Mg level may be a more accurate method to assess Mg level in patients with asthma. Hence, determination of Mg concentration in erythrocytes may be used in evaluation of asthma pathophysiology. There are recommendations for using intravenous Mg sulfate in acute asthma, and this study supports the rational for using it in emergency departments for acute

  4. Associations of erythrocyte fatty acid patterns with insulin resistance.

    Science.gov (United States)

    Bigornia, Sherman J; Lichtenstein, Alice H; Harris, William S; Tucker, Katherine L

    2016-03-01

    Synergistic or additive effects or both on cardiometabolic risk may be missed by examining individual fatty acids (FAs). A pattern analysis may be a more useful approach. In addition, it remains unclear whether erythrocyte FA composition relates to insulin resistance among Hispanics/Latinos. We derived erythrocyte FA patterns for a Puerto Rican cohort and examined their association with diet and insulin resistance in cross-sectional and prospective analyses. At baseline, principal components analysis was used to derive factor patterns with the use of 24 erythrocyte FAs from 1157 participants of the Boston Puerto Rican Health Study (aged 45-75 y). Dietary intake was assessed with a validated semiquantitative food-frequency questionnaire. The homeostasis model assessment of insulin resistance (HOMA-IR) was calculated at baseline and at the 2-y follow-up. Relations between FA patterns and HOMA-IR were analyzed in a sample of 922 participants with available data. Five FA patterns were derived, differentiated by 1) relatively high de novo lipogenesis (DNL) FAs and low n-6 (ω-6) FAs, 2) high very-long-chain saturated FAs, 3) high n-3 (ω-3) FAs, 4) high linoleic acid and low arachidonic acid, and 5) high trans FAs. The DNL pattern was positively correlated with sugar and inversely with n-6 and monounsaturated FA intakes. Only the DNL pattern was positively related to baseline HOMA-IR [adjusted geometric means (95% CIs) for quartiles 1 and 4: 1.72 (1.58, 1.87) and 2.20 (2.02, 2.39); P-trend insulin sensitivity in a Hispanic/Latino cohort. © 2016 American Society for Nutrition.

  5. Dietary plasmalogen increases erythrocyte membrane plasmalogen in rats

    Directory of Open Access Journals (Sweden)

    Mawatari Shiro

    2012-11-01

    Full Text Available Abstract Background Many disorders with plasmalogen deficiency have been reported. Replenishment or replacement of tissue plasmalogens of these disorders would be beneficial to the patients with these disorders, but effects of dietary plasmalogen on mammals have not been reported. Methods Plasmalogens were purified from chicken skin. The purified plasmalogens consisted of 96.4% ethanolamine plasmalogen (PlsEtn, 2.4% choline plasmalogen (PlsCho and 0.5% sphingomyelin (SM. A diet containing 0.1% the purified plasmalogens (PlsEtn diet was given to rats. Relative composition of phospholipids was measured by a high performance liquid chromatography (HPLC method that can separate intact plasmalogens and all other phospholipid classes by a single chromatographic run. Results The PlsEtn diet given to Zucker diabetic fatty (ZDF rats for 4 weeks caused decreases of plasma cholesterol and plasma phospholipid as compared to control diet. The other routine laboratory tests of plasma including triacylglycerol, glucose, liver and renal functions, albumin, and body weight were not different. Relative compositions of erythrocyte PlsEtn and phosphatidylethanolamine (PE increased, and that of phosphatidylcholine (PC decreased in PlsEtn diet group. The PlsEtn diet given to normal rats for 9 weeks again caused decrease of plasma cholesterol and phospholipid, and it induced increase of relative composition of PlsEtn of the erythrocyte membrane. The other routine laboratory tests of plasma and body weight were not different. Conclusions Dietary PlsEtn increases relative composition of PlsEtn of erythrocyte membranes in normal and ZDF rats, and it causes decreases of plasma cholesterol and plasma phospholipids. Dietary PlsEtn for 9 weeks seemingly causes no adverse effect to health of normal rats.

  6. Phosphatidylserine externalization and procoagulant activation of erythrocytes induced by Pseudomonas aeruginosa virulence factor pyocyanin.

    Science.gov (United States)

    Qadri, Syed M; Donkor, David A; Bhakta, Varsha; Eltringham-Smith, Louise J; Dwivedi, Dhruva J; Moore, Jane C; Pepler, Laura; Ivetic, Nikola; Nazi, Ishac; Fox-Robichaud, Alison E; Liaw, Patricia C; Sheffield, William P

    2016-04-01

    The opportunistic pathogen Pseudomonas aeruginosa causes a wide range of infections in multiple hosts by releasing an arsenal of virulence factors such as pyocyanin. Despite numerous reports on the pleiotropic cellular targets of pyocyanin toxicity in vivo, its impact on erythrocytes remains elusive. Erythrocytes undergo an apoptosis-like cell death called eryptosis which is characterized by cell shrinkage and phosphatidylserine (PS) externalization; this process confers a procoagulant phenotype on erythrocytes as well as fosters their phagocytosis and subsequent clearance from the circulation. Herein, we demonstrate that P. aeruginosa pyocyanin-elicited PS exposure and cell shrinkage in erythrocyte while preserving the membrane integrity. Mechanistically, exposure of erythrocytes to pyocyanin showed increased cytosolic Ca(2+) activity as well as Ca(2+) -dependent proteolytic processing of μ-calpain. Pyocyanin further up-regulated erythrocyte ceramide abundance and triggered the production of reactive oxygen species. Pyocyanin-induced increased PS externalization in erythrocytes translated into enhanced prothrombin activation and fibrin generation in plasma. As judged by carboxyfluorescein succinimidyl-ester labelling, pyocyanin-treated erythrocytes were cleared faster from the murine circulation as compared to untreated erythrocytes. Furthermore, erythrocytes incubated in plasma from patients with P. aeruginosa sepsis showed increased PS exposure as compared to erythrocytes incubated in plasma from healthy donors. In conclusion, the present study discloses the eryptosis-inducing effect of the virulence factor pyocyanin, thereby shedding light on a potentially important mechanism in the systemic complications of P. aeruginosa infection. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  7. Decreased erythrocyte superoxide dismutase in elderly men with early nuclear cataract

    Directory of Open Access Journals (Sweden)

    Rose Rose

    2015-12-01

    Full Text Available BACKGROUND Imbalance between oxidative processes and antioxidant defenses has been considered to play a role in cataractogenesis, particularly in diabetes patients. Superoxide dismutase (SOD is an important precursor for oxidative stress in the human lens, and its activity is mainly dependent on the copper and zinc levels in the body. The aim of this study was to compare erythrocyte SOD, erythrocyte zinc and total serum testosterone levels in male patients with early senile nuclear cataract and evaluate the correlations between the parameters in all subjects. METHODS A community-based study of cross-sectional design was conducted at Cilandak District Primary Health Center where 52 adult and 17 elderly men with early senile nuclear cataract were chosen as the study subjects. Erythrocyte SOD, erythrocyte zinc, serum testosterone, and fasting blood glucose (FBG levels were measured in all subjects. Nuclear cataract stage was assessed with the Pentacam® instrument (Oculus, Germany. Independent Student t test and Pearson’s correlation were used to analyze the results. RESULTS Erythrocyte SOD level was significantly decreased in elderly men compared to adult men (p=0.014. Erythrocyte zinc, serum testosterone and FBG did not differ significantly in adult and elderly males (at p=0.304; p=0.145;and p=0.376, respectively. Erythrocyte SOD activity was significantly associated with erythrocyte zinc level (r=0.486; p=0.048. CONCLUSIONS Lower erythrocyte SOD activity was found in elderly males than in adult males with early nuclear cataract. There was a relationship between erythrocyte SOD and erythrocyte zinc level in elderly males with early nuclear cataract.

  8. Probing Volume Changes and the Intracellular Water in Single Erythrocytes

    Science.gov (United States)

    Park, Sanghoon; Arora, Silki; Mauser, Jennifer; Chakrabarti, Debopam; Schulte, Alfons

    2012-02-01

    In the living cell, water is one of the most abundant substances, and cells have developed very efficient machinery for transporting water in and out. Erythrocytes can undergo large, but reversible, volume changes under hydrostatic pressure and a possible mechanism may involve transport of water. We employ confocal micro-Raman spectroscopy over the frequency range from 150 to 4000 cm-1 to probe both the intracellular hemoglobin and water in individual red blood cells under physiological conditions. We investigate changes in the OH stretch bands near 3400 cm-1 due to the cellular water. Results of experiments that employ variations in external parameters such as pressure will be presented.

  9. [Presentation of a method of interpreting erythrocyte deformability].

    Science.gov (United States)

    Cortinovis, A; Crippa, A; Sciacca, V; Caravaggio, V

    1988-05-01

    The physical principles of a method based on a haematic double filtration, according to Reid classic technique is explained. The aim is to determine a method for researching the characteristics of erythrocytic deformability, without changing the original medium, exoerythrocytic essential component of the membrane physiochemical quality and intraerythrocytic for the fast, active exchanges, after an evaluation of different techniques and instrumentation. A practical example for calculating the factor of correction, with reference to personal material, is made. This method has the advantage that it does not need the manipulation of the sample and does not delay the determination.

  10. Effects of Alcohol on Membrane Fluidity of Human Erythrocyte

    OpenAIRE

    Mori, Ichiya; Hiramatsu, Midori; Toda, Naomi; Koide, Yayoi; Miyagawa, Fumio

    1994-01-01

    Membrane fluidity in human erythrocytes was measured by a spin label method using an electron spin resonance spectrometer in healthy volunteers after ingestion of alcohol (1.5 ml of whisky/kg body weight). Fluidity in the lipid bilayer closer to the hydrophilic face decreased at 30 min and 90 min, and fluidity in the hydrophobic core decreased at 90 min after ingestion of alcohol. In the same experiment, the level of thiobarbituric acid reactive substances in the serum decreased 30 min after ...

  11. Anomalous diffusion of erythrocytes in the presence of polyvinylpyrrolidone.

    Science.gov (United States)

    Fritz, O G

    1984-01-01

    The diffusion coefficient of erythrocytes was measured using quasi-elastic light-scattering (QELS) techniques. The cells were suspended in phosphate-buffered saline solutions with and without a macromolecule, polyvinylpyrrolidone (PVP[360]). In the presence of the PVP(360) an anomalously high diffusion coefficient was measured for metabolizing cells with a normal transmembrane potential. The results are in agreement with experiments on rouleau formation by red blood cells and are supportive of the hypothesis of a long-range coherent interaction between metabolically active biological cells. Images FIGURE 8 FIGURE 9 FIGURE 10 PMID:6478035

  12. Erythrocyte volume in acidified venous blood from exercising limbs.

    Science.gov (United States)

    Van Beaumont, W.; Rochelle, R. H.

    1973-01-01

    Five male volunteers performed arm exercises in the sitting position by cranking the pedals of a bicycle ergometer at 50 revolutions per min. The initial mechanical work load of 0 kgm/min was increased every minute by 75 kgm/min until exhaustion occurred. The data obtained show a significant acidification of the venous blood from the working arms and a substantial increase in venous pCO2 during this type of muscular activity. However, the erythrocyte volume remained unaltered during the exercise.

  13. The aeolian dust accumulation curve

    NARCIS (Netherlands)

    Goossens, D.

    2001-01-01

    This article presents a simple physical concept of aeolian dust accumulation, based on the behaviour of the subprocesses of dust deposition and dust erosion. The concept is tested in an aeolian dust wind tunnel. The agreement between the accumulation curve predicted by the model and the accumulation

  14. The Antiproton Accumulator (AA)

    CERN Multimedia

    1980-01-01

    Section 06 - 08*) of the AA where the dispersion (and hence the horizontal beam size) is large. One can distinguish (left to right): A vacuum-tank, two bending magnets (BST06 and BST07 in blue) with a quadrupole (QDN07, in red) in between, another vacuum-tank, a wide quadrupole (QFW08) and a further tank . The tanks are covered with heating tape for bake-out. The tank left of BST06 contained the stack core pickup for stochastic cooling (see 7906193, 7906190, 8005051), the two other tanks served mainly as vacuum chambers in the region where the beam was large. Peter Zettwoch works on BST06. *) see: H. Koziol, Antiproton Accumulator Parameter List, PS/AA/Note 84-2 (1984)

  15. Solids Accumulation Scouting Studies

    Energy Technology Data Exchange (ETDEWEB)

    Duignan, M. R.; Steeper, T. J.; Steimke, J. L.

    2012-09-26

    The objective of Solids Accumulation activities was to perform scaled testing to understand the behavior of remaining solids in a Double Shell Tank (DST), specifically AW-105, at Hanford during multiple fill, mix, and transfer operations. It is important to know if fissionable materials can concentrate when waste is transferred from staging tanks prior to feeding waste treatment plants. Specifically, there is a concern that large, dense particles containing plutonium could accumulate in poorly mixed regions of a blend tank heel for tanks that employ mixing jet pumps. At the request of the DOE Hanford Tank Operations Contractor, Washington River Protection Solutions, the Engineering Development Laboratory of the Savannah River National Laboratory performed a scouting study in a 1/22-scale model of a waste staging tank to investigate this concern and to develop measurement techniques that could be applied in a more extensive study at a larger scale. Simulated waste tank solids: Gibbsite, Zirconia, Sand, and Stainless Steel, with stainless steel particles representing the heavier particles, e.g., plutonium, and supernatant were charged to the test tank and rotating liquid jets were used to mix most of the solids while the simulant was pumped out. Subsequently, the volume and shape of the mounds of residual solids and the spatial concentration profiles for the surrogate for heavier particles were measured. Several techniques were developed and equipment designed to accomplish the measurements needed and they included: 1. Magnetic particle separator to remove simulant stainless steel solids. A device was designed and built to capture these solids, which represent the heavier solids during a waste transfer from a staging tank. 2. Photographic equipment to determine the volume of the solids mounds. The mounds were photographed as they were exposed at different tank waste levels to develop a composite of topographical areas. 3. Laser rangefinders to determine the volume of

  16. In vitro suppression of spontaneous erythrocyte autoimmune responses with lymphocytes activated with concanavalin A

    Energy Technology Data Exchange (ETDEWEB)

    Ramshaw, I.A.; Woodsworth, M.; Eidinger, D.

    1979-01-01

    When normal mouse spleen cells are cultured in vitro, large numbers of cells develop that produce antibody toward antigens found on bromelain-treated mouse erythrocytes (BrMRBC). The in vitro culture also generates T cells that mediate DTH toward these antigens. We have suggested that under in vivo conditions, suppressor T cells maintain these immune responses at a low level but that this suppression wanes when the cells are cultured in vitro. The present study examines the effect of concanavalin A (Con A) on the in vitro development of humoral and cell-mediated immunity to BrMRBC. Mitogenic concentrations of Con A prevented the development of both the PFC and T/sub DTH/ responses toward BrMRBC. The Con A-induced suppression was due to the induction of suppressor T cells; thus the addition of Con A-activated cells to fresh spleen cell cultures prevented the development of both the PFC and T/sub DTH/ response against BrMRBC.

  17. No decreased erythrocyte deformability in type 1 (insulin-dependent) diabetes, either by filtration or by ektacytometry

    NARCIS (Netherlands)

    Schut, N. H.; van Arkel, E. C.; Hardeman, M. R.; Bilo, H. J.; Michels, R. P.; Vreeken, J.

    1993-01-01

    A lower erythrocyte deformability, which causes impairment of the microcirculation, is postulated to contribute to diabetic organ complications. Erythrocyte deformability was measured in four groups of type 1 (insulin-dependent) diabetic subjects and 30 controls by filtration and ektacytometry.

  18. Electron Pathways through Erythrocyte Plasma Membrane in Human Physiology and Pathology: Potential Redox Biomarker?

    Directory of Open Access Journals (Sweden)

    Elena Matteucci

    2007-01-01

    Full Text Available Erythrocytes are involved in the transport of oxygen and carbon dioxide in the body. Since pH is the influential factor in the Bohr-Haldane effect, pHi is actively maintained via secondary active transports Na+/H+ exchange and HC3 -/Cl- anion exchanger. Because of the redox properties of the iron, hemoglobin generates reactive oxygen species and thus, the human erythrocyte is constantly exposed to oxidative damage. Although the adult erythrocyte lacks protein synthesis and cannot restore damaged proteins, it is equipped with high activity of protective enzymes. Redox changes in the cell initiate various signalling pathways. Plasma membrane oxido-reductases (PMORs are transmembrane electron transport systems that have been found in the membranes of all cells and have been extensively characterized in the human erythrocyte. Erythrocyte PMORs transfer reducing equivalents from intracellular reductants to extracellular oxidants, thus their most important role seems to be to enable the cell respond to changes in intra- and extra-cellular redox environments.So far the activity of erythrocyte PMORs in disease states has not been systematically investigated. This review summarizes present knowledge on erythrocyte electron transfer activity in humans (health, type 1 diabetes, diabetic nephropathy, and chronic uremia and hypothesizes an integrated model of the functional organization of erythrocyte plasma membrane where electron pathways work in parallel with transport metabolons to maintain redox homeostasis.

  19. Effects of Polyelectrolyte Microcapsules with Different Surface Charge on Erythrocyte Sedimentation Rate.

    Science.gov (United States)

    Naumov, A A; Dubrovskii, A V; Potselueva, M M; Tikhonenko, S A

    2017-05-01

    Relationship between changes in the erythrocyte sedimentation rate in rats and concentration and charge of polyelectrolyte microcapsules was studied by the Panchenkov method. Positively charged microcapsules reduced erythrocyte sedimentation rate in a concentrationdependent manner. This effect was related to a decrease in the content of high-molecularweight proteins in the plasma due to their adsorption in positively charged microcapsules with polyacrylamide surface layer.

  20. In Vivo distribution of hydrocortisone over whole blood : A novel method for the extraction of erythrocytes

    NARCIS (Netherlands)

    Driessen, O.; Treuren, L.; Moolenaar, A.; Meijer, J.W.A.; Verheijen, P.

    1990-01-01

    Ten mg hydrocortisone (HC) was administered intravenously to a healthy volunteer after a dexamethasone suppresion test and HC concentrations were determined from 1-270 min in plasma, plasma water and on erythrocytes. HC was extracted front erythrocyte concentrates with high efficiency by HC-poor

  1. Erythrocyte migration and gap formation in rabbit blood clots in vitro.

    Science.gov (United States)

    Ueki, T; Yazama, F; Horiuchi, T; Yamada, M

    2008-04-01

    Thrombolytic agents must be carried by the blood circulation to thrombi to exert their functions. Structural gaps exist between blood vessels and thrombi or in the area surrounding thrombi. Therefore, information about fundamental gap formation at thrombotic areas is critically important for thrombolytic therapy. We previously reported that t-PA accelerates the activities of bovine erythrocytes and hemoglobin (Hb) towards bovine plasminogen activation. Here, we examined gap generation by observing morphological changes during thrombolytic processes in rabbit blood clots deformation of erythrocytes from blood clots and Hb transfer from erythrocytes to serum in vitro. Rabbit venous blood samples (1 ml) were stored under sterile conditions in glass tubes at 37 degrees C for 2, 24, 48 h, 1, and 2 weeks. We examined clot diameter, erythrocyte diameter and number as well as Hb volume in the serum, as well as histological changes in the clots. The diameter of blood clots did not change until 2 weeks after sampling. Erythrocyte diameter decreased within 48 h and at 2 weeks after sampling at the clot surface (p erythrocytes in the serum started to increase starting from 24 h after sampling (p erythrocyte envelope became disrupted and cytoplasm started to flow through pores into the serum at 24 h. The results indicated that blood clots are reduced due to clot retraction, erythrocyte dissociation and cytoplasm leakage without a distinct fibrinolytic reaction. These results indicated that gaps start to form between 2 and 24 h after blood clotting.

  2. Platelet-independent adhesion of calcium-loaded erythrocytes to von Willebrand factor

    NARCIS (Netherlands)

    Smeets, M.W.J. (Michel W.J.); R. Bierings (Ruben); Meems, H. (Henriet); F.P.J. Mul (F. P J); D. Geerts (Dirk); A.P.J. Vlaar (Alexander); J. Voorberg (Jan); P.L. Hordijk (Peter )

    2017-01-01

    textabstractAdhesion of erythrocytes to endothelial cells lining the vascular wall can cause vaso-occlusive events that impair blood flow which in turn may result in ischemia and tissue damage. Adhesion of erythrocytes to vascular endothelial cells has been described in multiple hemolytic disorders,

  3. Sesquicentennial of the birth of Edmund Faustinus Biernacki, a discoverer of the erythrocyte sedimentation rate.

    Science.gov (United States)

    Kucharz, Eugeniusz J

    2017-01-01

    Edmund Faustinus Biernacki (1866-1911) was a Polish physician and philosopher of medicine. He described erythrocyte sedimentation, designed equipment to measure the erythrocyte sedimentation rate, and applied it to clinical practice. His contribution to the development of one of the most commonly used medical laboratory tests is forgotten, and the test is attributed to other scientists.

  4. An ex vivo study of nitric oxide efflux from human erythrocytes in both genders.

    Science.gov (United States)

    Duarte, Catarina; Napoleão, Patrícia; Freitas, Teresa; Saldanha, Carlota

    2016-01-01

    Acetylcholinesterase (AChE) is located on outer surface of erythrocyte membrane. Gender-related differences in erythrocyte AChE enzyme activity had been verified in young adults. It is also known that binding of acetylcholine (ACh) with AChE on erythrocyte membrane initiates a signal transduction mechanism that stimulates nitric oxide (NO) efflux. This ex vivo study was done to compare the amount of NO efflux obtained from erythrocytes of healthy donors in males and females. We included 66 gender age-matched healthy donors (40-60 years old). We performed quantification of erythrocyte NO efflux from erythrocytes and of the membrane AChE enzyme activity. There are no significant differences in NO efflux from erythrocytes between men and women. Regarding AChE enzyme activity values, in this range of age, no differences between genders were obtained. However, the values of AChE enzyme activity in the third quartile of NO efflux values were significantly higher (p gender. For the same range of values of NO efflux from erythrocytes, in both gender, it was verified higher values of AChE enzyme activity in women.

  5. CD47 in Erythrocyte Ageing and Clearance - the Dutch Point of View

    NARCIS (Netherlands)

    Burger, Patrick; de Korte, Dirk; van den Berg, Timo K.; van Bruggen, Robin

    2012-01-01

    Recently, an important role for CD47, a well-known 'don't eat me' signal, in the clearance of aged erythrocytes was revealed. Experimental data support the conversion of CD47 from a 'don't eat me' to an 'eat me' signal through a conformational change in CD47. Intriguingly, erythrocyte phagocytosis

  6. The erythrocyte sedimentation rate, rouleaux formation and hyperviscosity syndrome. Theory and fact.

    Science.gov (United States)

    Ballas, S K

    1975-01-01

    Uncomplicated hyperviscosity syndrome secondary to hypergammaglobulinemic states seems to be associated with rouleaux formation on the peripheral blood film and a normal or near normal erythrocyte sedimentation rate. Conversely, the concomitant finding of rouleaux formation with a normal erythrocyte sedimentation rate is highly suggestive of the hyperviscosity syndrome. The theoretical and factual justifications for this hypothesis are presented.

  7. Host erythrocyte polymorphisms and exposure to Plasmodium falciparum in Papua New Guinea.

    NARCIS (Netherlands)

    Fowkes, F.J.; Michon, P.; Pilling, L.; Ripley, R.M.; Tavul, L.; Imrie, H.J.; Woods, C.M.; Mgone, C.S.; Luty, A.J.F.; Day, K.P.

    2008-01-01

    BACKGROUND: The protection afforded by human erythrocyte polymorphisms against the malaria parasite, Plasmodium falciparum, has been proposed to be due to reduced ability of the parasite to invade or develop in erythrocytes. If this were the case, variable levels of parasitaemia and rates of

  8. Plasmodium falciparum Erythrocyte Membrane Protein 1 Diversity in Seven Genomes – Divide and Conquer

    DEFF Research Database (Denmark)

    Rask, Thomas Salhøj; Hansen, Daniel Aaen; Theander, Thor G.

    2010-01-01

    The var gene encoded hyper-variable Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family mediates cytoadhesion of infected erythrocytes to human endothelium. Antibodies blocking cytoadhesion are important mediators of malaria immunity acquired by endemic populations. The development...

  9. Sheep erythrocyte membrane binding and transfer of long-chain fatty acids

    DEFF Research Database (Denmark)

    Bojesen, Inge Norby; Bojesen, Eigil

    1999-01-01

    Palmitic acid, oleic acid, linoleic acid, arachidonic acid, sheep erythrocyte ghosts, transporting elements, transport kinetics, fatty acid transport, transport rate constants......Palmitic acid, oleic acid, linoleic acid, arachidonic acid, sheep erythrocyte ghosts, transporting elements, transport kinetics, fatty acid transport, transport rate constants...

  10. Hemoglobinopathic Erythrocytes Affect the Intraerythrocytic Multiplication of Plasmodium falciparum In Vitro

    Science.gov (United States)

    Glushakova, Svetlana; Balaban, Amanda; McQueen, Philip G.; Coutinho, Rosane; Miller, Jeffery L.; Nossal, Ralph; Fairhurst, Rick M.; Zimmerberg, Joshua

    2014-01-01

    Background. The mechanisms by which α-thalassemia and sickle cell traits confer protection from severe Plasmodium falciparum malaria are not yet fully elucidated. We hypothesized that hemoglobinopathic erythrocytes reduce the intraerythrocytic multiplication of P. falciparum, potentially delaying the development of life-threatening parasite densities until parasite clearing immunity is achieved. Methods. We developed a novel in vitro assay to quantify the number of merozoites released from an individual schizont, termed the “intraerythrocytic multiplication factor” (IMF). Results. P. falciparum (3D7 line) schizonts produce variable numbers of merozoites in all erythrocyte types tested, with median IMFs of 27, 27, 29, 23, and 23 in control, HbAS, HbSS, and α- and β-thalassemia trait erythrocytes, respectively. IMF correlated strongly (r2 = 0.97; P erythrocytes was confirmed using clinical parasite isolates with different IMFs. Mathematical modeling of the effect of IMF on malaria progression indicates that the lower IMF in thalassemia trait erythrocytes limits parasite density and anemia severity over the first 2 weeks of parasite replication. Conclusions. P. falciparum IMF, a parasite heritable virulence trait, correlates with erythrocyte indices and is reduced in thalassemia trait erythrocytes. Parasite IMF should be examined in other low-indices erythrocytes. PMID:24688070

  11. Sequential, ordered acquisition of antibodies to Plasmodium falciparum erythrocyte membrane protein 1 domains

    DEFF Research Database (Denmark)

    Cham, Gerald K K; Turner, Louise; Lusingu, John

    2009-01-01

    The binding of erythrocytes infected with mature blood stage parasites to the vascular bed is key to the pathogenesis of malignant malaria. The binding is mediated by members of Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family. PfEMP1s can be divided into groups, and it has...

  12. Informativeness of polarization measurements in determining microphysical parameters of native erythrocyte populations

    Science.gov (United States)

    Kugeiko, M. M.; Smunev, D. A.

    2017-09-01

    The efficiency of polarized and nonpolarized radiation for determining microphysical parameters of native erythrocyte populations has been studied. On the basis of using regression relations between determined and measured parameters of native erythrocyte populations, possibilities of the simultaneous rapid determination of their average volume and average surface area, which can be used as a new diagnostic erythrocytometric parameter, are demonstrated.

  13. Expression of Plasmodium falciparum erythrocyte membrane protein 1 in experimentally infected humans

    DEFF Research Database (Denmark)

    Lavstsen, Thomas; Magistrado, Pamela; Hermsen, Cornelus C

    2005-01-01

    -encoded Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family, which is expressed on the surface of infected erythrocytes where it mediates binding to endothelial receptors. Thus, severe malaria may be caused by parasites expressing PfEMP1 variants that afford parasites optimal sequestration...

  14. The knocked-out erythrocyte sedimentation rate: periodontal abscess.

    Science.gov (United States)

    Sevinc, Alper; Bayindir, Yasar; But, Ayse

    2008-01-01

    The erythrocyte sedimentation rate (ESR) is a common but nonspecific test that is often used as an indicator of active disease. Infection of dental origin may be responsible for a number of cases in unresolved elevated ESR and fever etiology. Dental sepsis is the one of the potential causes of persistent fever that can escape detection. An 18-year-old female patient was admitted to the emergency room with complaints of headache, fever, nausea, and vomiting for the past four days. Erythrocyte sedimentation rate was 110 mm/h. She was started empirically on antibiotic treatment as no etiology was found. Four days later, while searching for the etiology of the fever, the patient experienced an acute pain in association with localizing symptoms in two decayed teeth. Oral examination revealed abscess formation in both teeth. Teeth were extracted and ESR was decreased to 95 mm/h on the day of the second extraction and to 60, 35, and 10 mm/h taken weekly. During the follow-up, she was in good health with no fever seen 3 months after treatment and her ESR was 15 mm/h. Dental infection should be considered as an unusual but very treatable cause of pyrexia of unknown origin.

  15. Reduced PKC α Activity Induces Senescent Phenotype in Erythrocytes

    Directory of Open Access Journals (Sweden)

    Rukmini B. Govekar

    2012-01-01

    Full Text Available The molecular mechanism mediating expression of senescent cell antigen-aggregated or cleaved band 3 and externalized phosphatidylserine (PS on the surface of aged erythrocytes and their premature expression in certain anemias is not completely elucidated. The erythrocytes with these surface modifications undergo macrophage-mediated phagocytosis. In this study, the role of protein kinase C (PKC isoforms in the expression of these surface modifications was investigated. Inhibition of PKC α by 30 μM rottlerin (R30 and 2.3 nM Gö 6976 caused expression of both the senescent cell marker-externalized PS measured by FACS analysis and aggregated band 3 detected by western blotting. In contrast to this observation, but in keeping with literature, PKC activation by phorbol-12-myristate-13-acetate (PMA also led to the expression of senescence markers. We explain this antithesis by demonstrating that PMA-treated cells show reduction in the activity of PKC α, thereby simulating inhibition. The reduction in PKC α activity may be attributed to the known downregulation of PMA-activated PKC α, caused by its membrane translocation and proteolysis. We demonstrate membrane translocation of PKC α in PMA-treated cells to substantiate this inference. Thus loss of PKC α activity either by inhibition or downregulation can cause surface modifications which can trigger erythrophagocytosis.

  16. Altered erythrocyte Na-K pump in anorectic patients

    Energy Technology Data Exchange (ETDEWEB)

    Pasquali, R.; Strocchi, E.; Malini, P.; Casimirri, F.; Ambrosioni, E.; Melchionda, N.; Labo, G.

    1985-07-01

    The status of the erythrocyte sodium pump was evaluated in a group of patients suffering from anorexia nervosa and a group of healthy female control subjects. Anorectic patients showed significantly higher mean values of digoxin-binding sites/cell (ie, the number of Na-K-ATPase units) with respect to control subjects while no differences were found in the specific /sup 86/Rb uptake (which reflects the Na-K-ATPase activity) between the two groups. A significant correlation was found between relative weight and the number of Na-K-ATPase pump units (r = -0.66; P less than 0.0001). Anorectic patients showed lower serum T3 concentrations (71.3 +/- 53 ng/dL) with respect to control subjects (100.8 +/- 4.7 ng/dL; P less than 0.0005) and a significant negative correlation between T3 levels and the number of pump units (r = -0.52; P less than 0.003) was found. This study therefore shows that the erythrocyte Na-K pump may be altered in several anorectic patients. The authors suggest that this feature could be interrelated with the degree of underweight and/or malnutrition.

  17. Modulation of Erythrocyte Plasma Membrane Redox System Activity by Curcumin

    Directory of Open Access Journals (Sweden)

    Prabhakar Singh

    2016-01-01

    Full Text Available Plasma membrane redox system (PMRS is an electron transport chain system ubiquitously present throughout all cell types. It transfers electron from intracellular substrates to extracellular acceptors for regulation of redox status. Curcumin, isolated from Curcuma longa, has modulatory effects on cellular physiology due to its membrane interaction ability and antioxidant potential. The present study investigates the effect of curcumin on PMRS activity of erythrocytes isolated from Wistar rats in vitro and in vivo and validated through an in silico docking simulation study using Molegro Virtual Docker (MVD. Effects of curcumin were also evaluated on level of glutathione (GSH and the oxidant potential of plasma measured in terms of plasma ferric equivalent oxidative potentials (PFEOP. Results show that curcumin significantly (p<0.01 downregulated the PMRS activity in a dose-dependent manner. Molecular docking results suggest that curcumin interacts with amino acids at the active site cavity of cytochrome b5 reductase, a key constituent of PMRS. Curcumin also increased the GSH level in erythrocytes and plasma while simultaneously decreasing the oxidant potential (PFEOP of plasma. Altered PMRS activity and redox status are associated with the pathophysiology of several health complications including aging and diabetes; hence, the above finding may explain part of the role of curcumin in health beneficial effects.

  18. Ankyrin is the major oxidised protein in erythrocyte membranes from end-stage renal disease patients on chronic haemodialysis and oxidation is decreased by dialysis and vitamin C supplementation.

    Science.gov (United States)

    Ruskovska, T; Bennett, S J; Brown, C R; Dimitrov, S; Kamcev, N; Griffiths, H R

    2015-02-01

    Chronically haemodialysed end-stage renal disease patients are at high risk of morbidity arising from complications of dialysis, the underlying pathology that has led to renal disease and the complex pathology of chronic kidney disease. Anaemia is commonplace and its origins are multifactorial, involving reduced renal erythropoietin production, accumulation of uremic toxins and an increase in erythrocyte fragility. Oxidative damage is a common risk factor in renal disease and its co-morbidities and is known to cause erythrocyte fragility. Therefore, we have investigated the hypothesis that specific erythrocyte membrane proteins are more oxidised in end-stage renal disease patients and that vitamin C supplementation can ameliorate membrane protein oxidation. Eleven patients and 15 control subjects were recruited to the study. Patients were supplemented with 2 × 500 mg vitamin C per day for 4 weeks. Erythrocyte membrane proteins were prepared pre- and post-vitamin C supplementation for determination of protein oxidation. Total protein carbonyls were reduced by vitamin C supplementation but not by dialysis when investigated by enzyme linked immunosorbent assay. Using a western blot to detect oxidised proteins, one protein band, later identified as containing ankyrin, was found to be oxidised in patients but not controls and was reduced significantly by 60% in all patients after dialysis and by 20% after vitamin C treatment pre-dialysis. Ankyrin oxidation analysis may be useful in a stratified medicines approach as a possible marker to identify requirements for intervention in dialysis patients.

  19. The unexpected effect of PEGylated gold nanoparticles on the primary function of erythrocytes

    Science.gov (United States)

    He, Zeng; Liu, Jiaxin; Du, Libo

    2014-07-01

    Polyethylene glycol-functionalized gold nanoparticles (PEGylated AuNPs) have been widely used as nanocarriers for the delivery of various drugs. However, little attention has been paid to whether the PEGylated AuNPs could affect the primary function of human erythrocytes, which is the main cellular component in the blood. In the current study, we show that both the deformability and oxygen-delivering ability of erythrocytes are decreased when treated with PEGyalted AuNPs of various sizes, which can be attributed to the interaction between PEGylated AuNPs and erythrocyte membranes. It is observed that the PEGylated AuNPs could also induce the aggregation of band-3 and the ATP decrease of erythrocytes. In addition, the PEGylated AuNPs can accelerate the loss of CD47 on erythrocyte membranes, possibly enhancing the senescent process of erythrocytes and the following clearance by SIRPα-expressing leukocytes in bloodstream. The results suggested that PEGylated AuNPs have the potential to affect the primary function of human erythrocytes, which should be considered when using them as drug carriers.Polyethylene glycol-functionalized gold nanoparticles (PEGylated AuNPs) have been widely used as nanocarriers for the delivery of various drugs. However, little attention has been paid to whether the PEGylated AuNPs could affect the primary function of human erythrocytes, which is the main cellular component in the blood. In the current study, we show that both the deformability and oxygen-delivering ability of erythrocytes are decreased when treated with PEGyalted AuNPs of various sizes, which can be attributed to the interaction between PEGylated AuNPs and erythrocyte membranes. It is observed that the PEGylated AuNPs could also induce the aggregation of band-3 and the ATP decrease of erythrocytes. In addition, the PEGylated AuNPs can accelerate the loss of CD47 on erythrocyte membranes, possibly enhancing the senescent process of erythrocytes and the following clearance by

  20. [Morphofunctional and biochemical properties of erythrocytes in early postnatal ontogenesis in rats in norm and after prenatal stress].

    Science.gov (United States)

    Golubeva, E K; Nazarov, S B; Tomilova, I K

    2011-07-01

    Morphofunctional and biochemical properties of erythrocyte membrane were investigated in early postnatal ontogenesis in rats in norm and after prenatal immobilization stress. The transient decrease of erythrocyte membranes stability was revealed in the control rats. The ability to erythrocyte transformation and the concentration of lipid peroxidation products are increased. It has been shown by an increase of percentage discocytes and lower lipid peroxidation level that the erythrocyte membrane of the rats after prenatal stress is more stable.

  1. Reduction of hydrogen peroxide-induced erythrocyte damage by Carica papaya leaf extract.

    Science.gov (United States)

    Okoko, Tebekeme; Ere, Diepreye

    2012-06-01

    To investigate the in vitro antioxidant potential of Carica papaya (C. papaya) leaf extract and its effect on hydrogen peroxide-induced erythrocyte damage assessed by haemolysis and lipid peroxidation. Hydroxyl radical scavenging activities, hydrogen ion scavenging activity, metal chelating activity, and the ferrous ion reducing ability were assessed as antioxidant indices. In the other experiment, human erythrocytes were treated with hydrogen peroxide to induce erythrocyte damage. The extract (at various concentrations) was subsequently incubated with the erythrocytes and later analysed for haemolysis and lipid peroxidation as indices for erythrocyte damage. Preliminary investigation of the extract showed that the leaf possessed significant antioxidant and free radical scavenging abilities using in vitro models in a concentration dependent manner (Ppapaya leaves possess significant bioactive potential which is attributed to the phytochemicals which act in synergy. Thus, the leaves can be exploited for pharmaceutical and nutritional purposes.

  2. Impaired erythrocyte filterability of spontaneously hypertensive rats: investigation by nickel filtration technique.

    Science.gov (United States)

    Ariyoshi, Kyoko; Maruyama, Toru; Odashiro, Keita; Akashi, Koichi; Fujino, Takehiko; Uyesaka, Nobuhiro

    2010-01-01

    Deformability of erythrocytes plays a key role in the impairment of the microcirculation in hypertension. However, erythrocyte deformability in spontaneously hypertensive rats (SHR) during development of hypertension has not been fully investigated so far. Erythrocyte filterability (whole cell deformability) was investigated in relation to blood pressure measured by the tail-cuff method in SHR and age-matched Wistar-Kyoto rats (WKY), using a highly sensitive and reproducible nickel mesh filtration technique. Impaired erythrocyte filterability was marked (37.0+/-17.5%) in prehypertensive young SHR (7 weeks of age) and sustained (51.6+/-13.3%) in hypertensive mature SHR (18 weeks of age), when compared with that of age-matched WKY (62.1+/-7.2% in 7 weeks of age, Perythrocytes, but the erythrocyte count was significantly (Perythrocyte filterability in SHR is considered to contribute to the development and maintenance of genetic hypertension. (Circ J 2010; 74: 129 - 136).

  3. The effects of superoxide dismutase knockout on the oxidative stress parameters and survival of mouse erythrocytes.

    Science.gov (United States)

    Grzelak, Agnieszka; Kruszewski, Marcin; Macierzyńska, Ewa; Piotrowski, Łukasz; Pułaski, Łukasz; Rychlik, Błazej; Bartosz, Grzegorz

    2009-01-01

    The erythrocytes of 12-month old Sod1 (-/-) mice showed an increased level of reactive oxygen species (ROS), as estimated by the degree of dihydroethidine and dihydrorhodamine oxidation, and the increased level of Heinz bodies. No indices of severe oxidative stress were found in the red blood cells and blood plasma of Sod1 (-/-) mice as judged from the lack of significant changes in the levels of erythrocyte and plasma glutathione, plasma protein thiol and carbonyl groups and thiobarbituric-acid reactive substances in the blood plasma. However, a decreased erythrocyte lifespan, increased reticulocyte count and splenomegaly were noted, indicating the importance of superoxide dismutase for maintaining erythrocyte viability. The levels of erythrocyte ROS and Heinz bodies and the reticulocyte count were indistinguishable in Sod1 (+/+) and Sod1 (+/-) mice, suggesting that a superoxide dismutase activity decrease to half of its normal value may be sufficient to secure the protective effects of the enzyme.

  4. A rapid method for counting nucleated erythrocytes on stained blood smears by digital image analysis

    Science.gov (United States)

    Gering, E.; Atkinson, C.T.

    2004-01-01

    Measures of parasitemia by intraerythrocytic hematozoan parasites are normally expressed as the number of infected erythrocytes per n erythrocytes and are notoriously tedious and time consuming to measure. We describe a protocol for generating rapid counts of nucleated erythrocytes from digital micrographs of thin blood smears that can be used to estimate intensity of hematozoan infections in nonmammalian vertebrate hosts. This method takes advantage of the bold contrast and relatively uniform size and morphology of erythrocyte nuclei on Giemsa-stained blood smears and uses ImageJ, a java-based image analysis program developed at the U.S. National Institutes of Health and available on the internet, to recognize and count these nuclei. This technique makes feasible rapid and accurate counts of total erythrocytes in large numbers of microscope fields, which can be used in the calculation of peripheral parasitemias in low-intensity infections.

  5. Hemolitic action of Naja naja atra cardiotoxin on erythrocytes from different animals

    Directory of Open Access Journals (Sweden)

    J. C. Troiano

    2006-01-01

    Full Text Available A comparative study on the sensitivity of erythrocytes from different vertebrate species (avian, mammalian and reptilian to the hemolytic action caused by cardiotoxin isolated from Naja naja atra venom was carried out. Cardiotoxin was able to induce direct hemolysis in washed erythrocytes from several animals, except for llama. The EC50 values from hemolysis of the most sensitive (cat and the most resistant (snake animal varied approximately tenfold. According to the cell behavior, it was possible to characterize four types of behavior: The first was observed in cat, horse and human cells; the second in rat, rabbit and dog erythrocytes; and the third only in llama erythrocytes, which were resistant to cardiotoxin concentrations up to 300 µg/ml. Finally, avian and reptilian erythrocytes were more resistant to cardiotoxin III-induced hemolysis than those of the mammalian species.

  6. [Effects of acute hypervolemic hemodilution and intraoperative blood salvage on erythrocyte morphology and biomechanics].

    Science.gov (United States)

    Zhang, Yiwen; Xinh, Zumin; Guo, Qiang; He, Zhongcheng

    2015-07-01

    To investigate the effects of acute hypervolemic hemodilution (AHH) and intraoperative blood salvage (IOBS) on the morphology and biomechanics of erythrocytes using atomic force microscopy (AFM). Blood samples were collected from 20 patients undergoing orthopedic surgery before operation (T1), immediately after AHH (T2), and after blood salvage (T3). AFM at nanometer resolution was used to examine the morphology and biomechanics of the collected erythrocytes. The blood samples collected at T1 showed a significantly lower ratio of heteromorphous erythrocytes than those collected at T2 and T3 [(2.6∓1.3)% vs (19.3∓1.6)% and (17.6∓1.4)%, Pbiomechanics of the single erythrocyte in salvaged blood and blood after AHH compared with those of venous blood. AHH and IOBS may cause significant changes in the morphology and biomechanics of erythrocytes in the salvaged blood.

  7. Acetylsalicylic acid (aspirin) and salicylic acid interaction with the human erythrocyte membrane bilayer induce in vitro changes in the morphology of erythrocytes.

    Science.gov (United States)

    Suwalsky, Mario; Belmar, Jessica; Villena, Fernando; Gallardo, María José; Jemiola-Rzeminska, Malgorzata; Strzalka, Kazimierz

    2013-11-01

    Despite the well-documented information, there are insufficient reports concerning the effects of salicylate compounds on the structure and functions of cell membranes, particularly those of human erythrocytes. With the aim to better understand the molecular mechanisms of the interaction of acetylsalicylic acid (ASA) and salicylic acid (SA) with cell membranes, human erythrocyte membranes and molecular models were utilized. These consisted of bilayers of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), representative of phospholipid classes located in the outer and inner monolayers of the human erythrocyte membrane, respectively. The capacity of ASA and SA to perturb the multibilayer structures of DMPC and DMPE was evaluated by X-ray diffraction while DMPC unilamellar vesicles (LUV) were studied by fluorescence spectroscopy. Moreover, we took advantage of the capability of differential scanning calorimetry (DSC) to detect the changes in the thermotropic phase behavior of lipid bilayers resulting from ASA and SA interaction with PC and PE molecules. In an attempt to further elucidate their effects on cell membranes, the present work also examined their influence on the morphology of intact human erythrocytes by means of defocusing and scanning electron microscopy, while isolated unsealed human erythrocyte membranes (IUM) were studied by fluorescence spectroscopy. Results indicated that both salicylates interact with human erythrocytes and their molecular models in a concentration-dependent manner perturbing their bilayer structures. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Macrodamage Accumulation Model for a Human Femur

    Directory of Open Access Journals (Sweden)

    Farah Hamandi

    2017-01-01

    Full Text Available The objective of this study was to more fully understand the mechanical behavior of bone tissue that is important to find an alternative material to be used as an implant and to develop an accurate model to predict the fracture of the bone. Predicting and preventing bone failure is an important area in orthopaedics. In this paper, the macrodamage accumulation models in the bone tissue have been investigated. Phenomenological models for bone damage have been discussed in detail. In addition, 3D finite element model of the femur prepared from imaging data with both cortical and trabecular structures is delineated using MIMICS and ANSYS® and simulated as a composite structure. The damage accumulation occurring during cyclic loading was analyzed for fatigue scenario. We found that the damage accumulates sooner in the multiaxial than in the uniaxial loading condition for the same number of cycles, and the failure starts in the cortical bone. The damage accumulation behavior seems to follow a three-stage growth: a primary phase, a secondary phase of damage growth marked by linear damage growth, and a tertiary phase that leads to failure. Finally, the stiffness of the composite bone comprising the cortical and trabecular bone was significantly different as expected.

  9. Alterations of erythrocyte rheology and cellular susceptibility in end stage renal disease: Effects of peritoneal dialysis.

    Directory of Open Access Journals (Sweden)

    Nesrin Zeynep Ertan

    Full Text Available In this study, we investigated the effects of peritoneal dialysis on hemorheological and hematological parameters and their relations with oxidant and antioxidant status of uremic patients. Hemorheological parameters (erythrocyte deformability, erythrocyte aggregation, osmotic deformability, blood and plasma viscosity were measured in patients with renal insufficiency undergoing peritoneal dialysis (PD and volunteers. Erythrocyte deformability, osmotic deformability and aggregation in both autologous plasma and 3% dextran 70 were measured by laser diffraction ektacytometry. Enzyme activities of glutathione peroxidase, superoxide dismutase and catalase were studied in erythrocytes; lipid peroxidation was studied by measuring the amount of malondialdehyde in both erythrocytes and plasma samples. Blood viscosity at native hematocrit was significantly lower in PD patients at all measured shear rates compared to controls, but it was high in PD patients at corrected (45% hematocrit. Erythrocyte deformability did not show any difference between the two groups. Osmotic deformability was significantly lower in PD patients compared to controls. Aggregation index values were significantly high in PD patients in plasma Catalase and glutathione peroxidase activities in erythrocytes were decreased in PD patients whereas superoxide dismutase activity was increased compared to controls. Malondialdehyde was significantly increased in erythrocytes and plasma samples of PD patients which also shows correlations with aggregation parameters. It has been concluded that erythrocytes in PD patients are more prone to aggregation and this tendency could be influenced by lipid peroxidation activity in patient's plasma. These results imply that uremic conditions, loss of plasma proteins and an increased risk of oxidative stress because of decreasing levels of antioxidant enzymes affect erythrocyte rheology during peritoneal dialysis. This level of distortion may have

  10. The Antiproton Accumulator (AA)

    CERN Multimedia

    1980-01-01

    A section of the AA where the dispersion (and hence the horizontal beam size) is large. One can distinguish (left to right): A large vacuum-tank, a quadrupole (QDN09*), a bending magnet (BST08), another vacuum-tank, a wide quadrupole (QFW08) and (in the background) a further bending magnet (BST08). The tanks are covered with heating tape for bake-out. The tank left of QDN09 contained the kickers for stochastic pre-cooling (see 790621, 8002234, 8002637X), the other one served mainly as vacuum chamber in the region where the beam was large. Peter Zettwoch works on QFW08. * see: H. Koziol, Antiproton Accumulator Parameter List, PS/AA/Note 84-2 (1984) See under 7911303, 7911597X, 8004261 and 8202324. For photos of the AA in different phases of completion (between 1979 and 1982) see: 7911303, 7911597X, 8004261, 8004608X, 8005563X, 8005565X, 8006716X, 8006722X, 8010939X, 8010941X, 8202324, 8202658X, 8203628X .

  11. Age sensitivity of NFkappaB abundance and programmed cell death in erythrocytes induced by NFkappaB inhibitors

    NARCIS (Netherlands)

    Ghashghaeinia, M.; Cluitmans, J.C.A.; Toulany, M.; Saki, M.; Koberle, M.; Lang, E.; Dreischer, P.; Biedermann, T.; Duszenko, M.; Lang, F.; Bosman, G.J.C.G.M.; Wieder, T.

    2013-01-01

    BACKGROUND/AIMS: Erythrocytes may enter eryptosis, a suicidal death characterized by cell shrinkage and phosphatidylserine exposure at the erythrocyte outer membrane. Susceptibility to eryptosis is enhanced in aged erythrocytes and stimulated by NFkappaB-inhibitors Bay 11-7082 and parthenolide. Here

  12. Hierarchical, domain type-specific acquisition of antibodies to Plasmodium falciparum erythrocyte membrane protein 1 in Tanzanian children

    DEFF Research Database (Denmark)

    Cham, Gerald K K; Turner, Louise; Kurtis, Jonathan D

    2010-01-01

    Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is a variant antigen expressed on the surface of malaria-infected erythrocytes. PfEMP1 attaches to the vascular lining and allows infected erythrocytes to avoid filtration through the spleen. Each parasite genome encodes about 60...

  13. Can preoperative erythrocyte sedimentation rate serve as an indicator for midterm adverse events after coronary bypass grafting?

    Science.gov (United States)

    Togan, Turhan; Günday, Murat; Çiftçi, Özgür; Bingol, Hakan

    2015-04-28

    Erythrocyte sedimentation rate (ESR) may serve as a reasonably good indicator for coronary heart disease as usually ESR is elevated in these patients. The measurement of ESR is a very simple and cheap laboratory test that can be performed in routine blood examinations. In this study, we investigated the association between preoperative erythrocyte sedimentation rate and postoperative midterm adverse events after coronary artery bypass grafting (CABG). In the study, only male patients were included. The patients were divided into two groups: group 1 (preoperative sedimentation rate [<20 mm/h] normal [n = 232, 63.9%]) and group 2 (preoperative sedimentation rate [>20 mm/h] above normal [n = 131, 36.1%]). The hemogram and biochemistry panel values were measured one day before operation, on the postoperative first day, on the postoperative seventh day, and on the postoperative third month. Among the laboratory values, there was a statistically significant difference between the two groups with respect to postoperative first-day ESR and postoperative third-month high-sensitivity C-reactive protein (P < .05). In terms of postoperative morbidity, there was also a statistically significant difference (P < .05) between the two groups with regard to pleural effusion, infection of the soft tissue over the sternum, pulmonary infection, return to the intensive care unit, rehospitalization, and mortality. Elevated preoperative sedimentation rate is associated with postoperative adverse events in patients who undergo CABG. For this purpose, we suggest that patients with higher sedimentation rates undergo detailed examination to prevent mortality and morbidity.

  14. Influence of iodine-containing radiographic contrast media on the phenotype of erythrocytes from different laboratory animal species.

    Science.gov (United States)

    Hiebl, B; Hopperdietzel, C; Hünigen, H; Dietze, K; Klein, S; Schreier, B; Jung, F

    2013-01-01

    It is well known that clinically relevant concentrations of iodine-containing radiographic contrast media (CM) induce morphological changes in human erythrocytes. However, there are only few reports about CM effects on erythrocytes of animals (e.g. mice, rats, rabbits, and pigs). Thus, two conventional iodine-containing CM (iodixanol, Visipaque™ 320; iomeprol, Iomeprol™ 350) were tested for their effects on the morphology of erythrocytes from these. After venous blood sampling and blood centrifugation, the autologous plasma was supplemented with 40 vol% CM. Then, a defined number of erythrocytes was incubated in this CM-supplemented plasma for 5 min at body temperature (37°C). Subsequently, 10 μL of the cell suspension were transferred to a purified glass slide and the number of discocytes, echinocytes, and acanthocytes was counted within a total number of 100 erythrocytes (40 fold primary magnification, transmitted light mode). Shape changes of the erythrocytes from all animal species strongly depended on the type of CM and compared to the effects which have already been described for human erythrocytes. Incubation in both CM resulted in morphological changes of the erythrocytes. Incubation in a iodixanol/plasma mixture induced the lowest echinocyte or acanthocyte formation. Porcine erythrocytes showed a much more distinct shape change than those of other animal species and humans. These results suggest erythrocytes from mice, rats, and rabbits are a suitable model system for a model system for human erythrocytes when CM effects on the cellular shape of erythrocytes have to be tested. The distinct deformation of the pig erythrocytes could be due to differences in the pig erythrocyte membrane or the physical and chemical constitution of pig erythrocytes.

  15. Parenting to Prevent Childhood Alcohol Use

    Science.gov (United States)

    ... Parenting to Prevent Childhood Alcohol Use Print Version Parenting to Prevent Childhood Alcohol Use Drinking alcohol undoubtedly ... drunk at least once by 12th grade. 1 Parenting Style Accumulating evidence suggests that alcohol use—and ...

  16. A GBP 130 derived peptide from Plasmodium falciparum binds to human erythrocytes and inhibits merozoite invasion in vitro

    Directory of Open Access Journals (Sweden)

    Jorge E Suarez

    2000-08-01

    Full Text Available The malarial GBP 130 protein binds weakly to intact human erythrocytes; the binding sites seem to be located in the repeat region and this region's antibodies block the merozoite invasion. A peptide from this region (residues from 701 to 720 which binds to human erythrocytes was identified. This peptide named 2220 did not bind to sialic acid; the binding site on human erythrocyte was affected by treatment with trypsin but not by chymotrypsin. The peptide was able to inhibit Plasmodium falciparum merozoite invasion of erythrocytes. The residues F701, K703, L705, T706, E713 (FYKILTNTDPNDEVERDNAD were found to be critical for peptide binding to erythrocytes.

  17. Ameliorative Effects of Caffeic Acid on Lead Accumulation and Oxidative Stress in Lead-Exposed Mice

    Directory of Open Access Journals (Sweden)

    Maryam Lotfi-Ghahramanloo

    2016-05-01

    Full Text Available Background The currently approved treatment for lead toxicity is chelation therapy to reduce the burden of the toxic effects of lead, but the safety and efficacy of the various chelating agents may be questioned. Objectives This study was aimed to evaluate the effects of caffeic acid, a dietary non-flavonoid phenolic acid, on lead accumulation and lead-induced oxidative stress in mice. Materials and Methods In this experimental study, 24 mice were divided into four groups. Group 1 served as control. Mice in group 2 received water containing 1000 ppm lead acetate. Group 3 animals received caffeic acid (60 mg/kg body weight i.p. during lead treatment. Mice in group 4 only received caffeic acid. At the end of the experiment (18 days, blood samples were drawn and the levels of lead and some oxidative-stress related parameters were measured. Results Blood Pb concentration increased significantly in group 2 as compared to control group. Lead exposure caused significant increase of malondialdehyde and decrease of glutathione concentrations in erythrocyte haemolysate as compared to control group. Although caffeic acid was effective in normalization of the attenuated levels of erythrocytic glutathione, its administration had no significant effect in decreasing the augmented levels of erythrocytic malondialdehyde in group 3. Values of other measured parameters including erythrocytic activities of glutathione peroxidase and superoxide dismutase did not change significantly among experimental groups. Conclusions Present results show some beneficial effects of caffeic acid against lead poisoning and it can be thus proposed as a potential prophylactic treatment for amelioration of lead toxicity.

  18. Influence of suspension osmolarity and erythrocyte volume on cell deformability

    Energy Technology Data Exchange (ETDEWEB)

    Feo, C. (Institut de Pathologie Cellulaire, INSERM, 94 - Kremlin-Bicetre (France)); Phillips, W.M. (School of Mechanical Engineering, Purdue University, West Lafayette, IN (USA))

    1982-01-01

    Erythrocytes were suspended in dextran solutions of phosphate buffered saline with solution osmolarities from 400 to 20 mosM/kg. The dilute suspensions were subjected to linear shear and their deformation determined by laser diffractometry (Ektacytometer). Cell volumes were measured using a Coulter counter following fixation in glutaraldehyde to eliminate the influence of deformability on the volume measurement. Minimum deformability generally agreed with the maximum cellular volume produced by hypotonic solutions. However, reduced deformability was observed for both hyperosmotic and hypoosmotic conditions. The oncotic effect of the dextran delayed hemolysis to surprisingly low values of solution osmolarity. In contrast with the usual osmotic fragility results, in the hypotonic dextran solutions there was no evidence of hemoglobin release. At low shear stresses, deformability was found to be enhanced by reducing intracellular viscosity (via osmotic water transport into the cell). However, the maximum cellular deformation obtained at high shear stress was always less than for the normal discocyte at normal osmolarities.

  19. Clinical relevance of erythrocyte ferritin in microcytic anemias.

    Science.gov (United States)

    Vagace, Jose M; Peças, Antonio; Groiss, Jorge; Bento, Celeste; Ribeiro, Maria Leticia; Gervasini, Guillermo

    2015-03-10

    Erythrocyte ferritin (EF) reflects the balance between iron supply and its utilization for hemoglobin synthesis. This balance is altered in microcytosis. We aimed to evaluate the diagnostic value of both EF and the ratio (FRR) plasma ferritin (PF)/EF in these disorders. A total of 231 subjects participated in the study. Samples from 93 adult patients with different causes of microcytosis, 57 healthy subjects and 81 full-term newborns were analyzed to determine EF and PF concentrations and other hematological parameters. In patients with iron deficiency, and in contrast to PF, EF decreased only in the presence of anemia and in direct correlation with the degree of microcytosis (Pearson's panemia of inflammation than in those with thalassemia (p<10e-5), thus helping to discriminate between these disorders. EF and FRR are tools that may be useful in the diagnosis of the main causes of microcytosis. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Mechanisms and pathophysiological significance of eryptosis, the suicidal erythrocyte death.

    Science.gov (United States)

    Lang, Elisabeth; Lang, Florian

    2015-03-01

    Eryptosis, the suicidal erythrocyte death characterized by cell shrinkage and cell membrane scrambling, is stimulated by Ca(2+) entry through Ca(2+)-permeable, PGE2-activated cation channels, by ceramide, caspases, calpain, complement, hyperosmotic shock, energy depletion, oxidative stress, and deranged activity of several kinases (e.g. AMPK, GK, PAK2, CK1α, JAK3, PKC, p38-MAPK). Eryptosis is triggered by intoxication, malignancy, hepatic failure, diabetes, chronic renal insufficiency, hemolytic uremic syndrome, dehydration, phosphate depletion, fever, sepsis, mycoplasma infection, malaria, iron deficiency, sickle cell anemia, thalassemia, glucose 6-phosphate dehydrogenase deficiency, and Wilson's disease. Eryptosis may precede and protect against hemolysis but by the same token result in anemia and deranged microcirculation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. A Combined Numerical and Experimental Analysis on Erythrocyte Damage Mechanism in Microscale Flow

    Directory of Open Access Journals (Sweden)

    Di Zhang

    2013-01-01

    Full Text Available An experimental system was designed and completed to realize the visualization of erythrocyte suspension microscale flow in microchannel and obtain the geometric parameters. The numerical simulation of the flow in the microchannel was accomplished to obtain the distribution of the physical parameters. Combined with the experimental data, the fitted curves of the physical parameters and geometric parameters on the axis were achieved. By analyzing the energy balance of the erythrocyte, the curve of the elasticity modulus of the erythrocyte membrane was obtained. The mechanism of the hemolysis caused by collision was expounded. Besides, the comparison among different cases was completed, illustrating the influence of the flow rate on hemolysis. The result shows that the predominant force of longitudinal compression is the pressure difference per erythrocyte. The curve of the elasticity modulus indicates that the membrane elasticity rapidly decreases as the erythrocyte approaches to the wall. The erythrocyte membrane loses elasticity, indicating that the contractile protein is fragile to the compressive loading, which increases significantly with a higher flow rate, making the erythrocyte membrane more likely to fracture.

  2. In vitro erythrocyte oxidative damage of Morinda citrifolia L (noni leaves extract

    Directory of Open Access Journals (Sweden)

    Alicia Lagarto

    2013-06-01

    Full Text Available Slight decrease of hemoglobin and erythrocyte count was observed previously after subchronic oral dosing of Morinda citrifolia L leaves extract in rats. Induction of erythrocyte membrane damage could be the cause for these effects. Aims: The objective of this investigation was to assess the in vitro cytotoxicity of Morinda citrifolia L leaves extract and fractions on rat erythrocytes. Methods: Hemolytic damage was assayed in rat erythrocytes. Oxidative stress was assessed by measuring methemoglobin formation, thiobarbituric acid reactive substances (TBARS and enzyme antioxidant activities, superoxide dismutase (SOD and catalase (CAT. Results: Morinda citrifolia L extract caused no hemolysis and induced oxidative damage to red cells in vitro. Methemoglobin increase was observed at concentration between 2 and 8 mg/ml of the extract. Lipid peroxidation was increased and CAT and SOD activities were depleted indicating a possible increase of hydrogen peroxide and superoxide radicals in erythrocytes. Ethyl acetate, dichloromethane and butanol fraction did not cause methemoglobin formation while water fraction increased methemoglobin level at doses up to 6 mg/ml. Conclusions: We concluded that high doses of Morinda citrifolia L extract promote erythrocyte oxidative damage due to metabolites present in water fraction. These could be the cause of decreased erythrocyte and hemoglobin levels observed. [J Intercult Ethnopharmacol 2013; 2(3.000: 135-140

  3. Nucleated Teleost Erythrocytes Play an Nk-Lysin- and Autophagy-Dependent Role in Antiviral Immunity

    Science.gov (United States)

    Pereiro, Patricia; Romero, Alejandro; Díaz-Rosales, Patricia; Estepa, Amparo; Figueras, Antonio; Novoa, Beatriz

    2017-01-01

    With the exception of mammals, vertebrate erythrocytes are nucleated. Nevertheless, these cells are usually considered as mere carriers of hemoglobin. In this work, however, we describe for the first time an unrecognized role of teleost red blood cells (RBCs). We found that Nk-lysin (Nkl), an antimicrobial peptide produced by NK-cells and cytotoxic T-lymphocytes, was also expressed in flatfish turbot (Scophthalmus maximus) erythrocytes. Although the antiviral role of Nkl remains to be elucidated, we found a positive correlation between the transcription of nkl and the resistance to an infection with Rhabdovirus in a teleost fish. Surprisingly, Nkl was found to be present in the autophagolysosomes of erythrocytes, and therefore this higher resistance provided by Nkl could be related to autophagy. The organelles of RBCs are degraded through autophagy during the maturation process of these cells. In this work, we observed that the blockage of autophagy increased the replication of viral hemorrhagic septicemia virus in nucleated teleost erythrocytes, which suggests that this mechanism may also be a key process in the defense against viruses in these cells. Nkl, which possesses membrane-perturbing ability and was affected by this modulation of RBC autophagy, could also participate in this process. For the first time, autophagy has been described not only as a life cycle event during the maturation of erythrocytes but also as a pivotal antiviral mechanism in nucleated erythrocytes. These results suggest a role of erythrocytes and Nkl in the antiviral immunity of fish and other vertebrates with nucleated RBCs. PMID:29163526

  4. The study of the dynamics of erythrocytes under the influence of an external electric field

    Science.gov (United States)

    Mamaeva, Sargylana N.; Maksimov, Georgy V.; Antonov, Stepan R.

    2017-11-01

    A mathematical model is considered for the determination of the surface charge of an erythrocyte with its shape approximated by a surface of revolution of the second order, and the investigation of the dynamics of erythrocytes under the influence of an external electric field. In the first part of this work, the electrical surface charge of the erythrocyte of the patient was calculated with the assumption that the change in the shape and size of the red blood cells leads to stabilization of the electric field, providing a normal electrostatic repulsion. In the second part of the work, the research results of dynamics of changes in the morphology of erythrocytes under the influence of an external electric field depending on the values of their surface charge and resistance of blood plasma is presented. In the course of the work, the dependence of the surface charge of red blood cells from their shape and size is presented. The determination of the relationship between the value of the charge field and the surface of erythrocytes in norm and in pathology is shown. The dependence of the velocity of the erythrocytes on the characteristics of the external electric field, surface charge of the erythrocyte and properties of the medium is obtained. The results of this study can be applied indirectly to diagnose diseases and to develop recommendations for experimental studies of hemodynamics under the influence of various external physical factors.

  5. [Changes of physiological and biochemical characteristics of rat erythrocytes after blood loss].

    Science.gov (United States)

    Maslova, M N; Kazennov, A M; Katiukhin, L N; Novozhilov, A V; Skverchinskaia, E A; Tavrovskaia, T V

    2007-01-01

    In experiments of Wistar male rats, changes are studied of erythrocyte hematological, biochemical (activitities of transport ATPases), and rheological properties (capability for aggregation and deformability) 7 days after bloodletting of 12-15 % of the total blood mass. It has been shown that alongside with an elevation of erythrocyte volume and of the number of immature cells - reticulocytes, there was a statistically significant increase of Na,K-ATPase and Ca-ATPase activities in the whole erythrocytes and their membrane preparations - ghosts, the increment of activity in the case of Na,K-ATPase being essentially higher in the whole cells. This indicates the appearance of an enzyme activator inside the erythrocytes. There are also revealed a decrease of firmness of erythrocyte aggregates, a deceleration of spontaneous aggregation, and an increase of index of erythrocyte deformability. The conclusion is made that changes of erythrocyte rheological properties are interconnected with changes of the Na,K-ATPase activity and are directed to optimization of blood circulation in large vessels and capillary network.

  6. Plasmodium falciparum acid basic repeat antigen (ABRA) peptides: erythrocyte binding and biological activity.

    Science.gov (United States)

    Curtidor, H; Urquiza, M; Suarez, J E; Rodriguez, L E; Ocampo, M; Puentes, A; Garcia, J E; Vera, R; Lopéz, R; Ramirez, L E; Pinzon, M; Patarroyo, M E

    2001-08-14

    Non overlapping 20-mer peptides, covering the complete sequence of acid basic repeat antigen (ABRA) of Plasmodium falciparum, were synthesised and tested in binding assays to erythrocytes. Five peptides localised in the N-terminal region coded 2148 (121LQSHKKLIKALKKNIESYQN(140)), 2149 (141KKHLIYKNKSYNPLLLSCVK(160)), 2150 (161KMNMLKENVDYIQKNQNLFK(180)), 2152 (201YKSQGHKKETSQNQNENNDN(220)) and 2153 (221QKYQEVNDEDDVNDEEDTND(240)) specifically bind to erythrocytes. These peptides bind independently of the peptide and erythrocyte charge, with high affinity (Kd between 70 and 180 nM) and the hydrophobic interaction is important for this binding ( approximately 30% hydrophobic critical residues). These results allow us define a specific erythrocyte binding region (residues 121-240), which may bound to at least three different binding sites on erythrocytes. Peptide 2153 shares the underlined sequence 221QKYQEVNDEDDVNDEEDTND(240) with an earlier 18-mer peptide recognised by human exposed sera. Peptides number 2148 and 2149 in vitro inhibit erythrocyte invasion by merozoites. We found that 2149 peptide and some of its glycine analogues show specific haemolytic and/or antimicrobial activity. We discuss a possible role of ABRA or its regions in the merozoite invasion of erythrocyte.

  7. Deoxygenation Affects Composition of Membrane-Bound Proteins in Human Erythrocytes

    Directory of Open Access Journals (Sweden)

    Oksana G. Luneva

    2016-06-01

    Full Text Available Background/Aims: ATP release from erythrocyte plays a key role in hypoxia-induced elevation of blood flow in systematic circulation. We have previously shown that hemolysis contributes to erythrocyte ATP release triggered by several stimuli, including hypoxia, but the molecular mechanisms of hypoxia-increased membrane fragility remain unknown. Methods: In this study, we compared the action of hypoxia on hemolysis, ATP release and the composition of membrane-bound proteins in human erythrocytes. Results: Twenty minutes incubation of human erythrocytes in the oxygen-free environment increased the content of extracellular hemoglobin by ∼1.5 fold. Paired measurements of hemoglobin and ATP content in the same samples, showed a positive correlation between hemolysis and ATP release. Comparative analysis of SDS-PAGE electrophoresis of erythrocyte ghosts obtained under control and deoxygenated conditions revealed a ∼2-fold elevation of the content of membrane-bound protein with Mr of ∼60 kDa. Conclusion: Deoxygenation of human erythrocytes affects composition of membrane-bound proteins. Additional experiments should be performed to identify the molecular origin of 60 kDa protein and its role in the attenuation of erythrocyte integrity and ATP release in hypoxic conditions.

  8. Identification of Babesia bigemina infected erythrocyte surface antigens containing epitopes conserved among strains.

    Science.gov (United States)

    Shompole, S; McElwain, T F; Jasmer, D P; Hines, S A; Katende, J; Musoke, A J; Rurangirwa, F R; McGuire, T C

    1994-03-01

    The presence of previously uncharacterized antigens (new antigens) on the surface of intact erythrocytes infected with three strains of Babesia bigemina from Kenya and one each from Puerto Rico, Mexico, St. Croix, and Texcoco-Mexico was demonstrated by indirect immunofluorescent antibody (IFA) reactions. These antigens were not strain specific because antibodies in bovine immune serum to either the Mexico or Kenya isolates reacted with all seven strains tested. Homologous and heterologous immune serum antibodies bound a maximum of 83% and 55%, respectively, of intact erythrocytes infected with the Kenya-Ngong strain but not uninfected erythrocytes. Both sera caused agglutination of only infected erythrocytes. Antibodies eluted from the surface of glutaraldehyde (0.25%) fixed infected erythrocytes had IFA reaction patterns among strains similar to those of immune sera before elution. Eluted antibodies were used to determine if these antigens were protein and encoded by B. bigemina. Eluted antibodies bound seven parasite-encoded proteins of 240, 220, 66, 62, 58, 52 and 38 kDa in an erythrocyte surface-specific immunoprecipitation reaction of 35S-methionine labelled proteins. It was concluded that the surface of B. bigemina infected erythrocytes had parasite-encoded proteins and that these proteins had surface exposed epitopes that were conserved among the seven strains examined which were from two continents.

  9. Hereditary spherocytosis and elliptocytosis associated with prosthetic heart valve replacement: rheological study of erythrocyte modifications.

    Science.gov (United States)

    Caprari, Patrizia; Tarzia, Anna; Mojoli, Giorgio; Cianciulli, Paolo; Mannella, Emilio; Martorana, Maria Cristina

    2009-04-01

    The implantation of a prosthetic heart valve (HVP) in patients with hereditary spherocytosis (HS) and hereditary elliptocytosis (HE) is rare, and the changes in the structure and deformability of erythrocytes that follow implantation in these patients have been poorly described. In the present study, the erythrocytes in HS and HE patients with mechanical HVP were compared to the erythrocytes in patients with only congenital membrane defects, in terms of biochemical modifications and rheological behaviour. Integral and cytoskeletal erythrocyte membrane proteins were studied, and blood viscosity (shear rate/shear stress ratio), aggregation ratio [eta(1 s(-1))/eta(200 s(-1))], and red cell visco-elasticity were determined. Valve replacement with a mechanical prosthesis worsened anaemia and resulted in a change in haemolysis, from sub-clinical to evident. The rheological investigation of erythrocytes from HS patients confirmed the characteristic increased viscosity and aggregation ratio and the decreased deformability. The rheological behaviour of erythrocytes from patients with HVP showed a decrease in viscosity and an increase in elastic modulus. In these patients, the prosthesis seems to have induced traumatic damage to the erythrocyte membrane, leading to fragmentation and lysis, which in turn modified rheological parameters. The biochemical and rheological investigation allowed us to understand the clinical and haematological pictures of the patients and to describe the role played by different factors in haemolytic anaemia.

  10. Nucleated Teleost Erythrocytes Play an Nk-Lysin- and Autophagy-Dependent Role in Antiviral Immunity.

    Science.gov (United States)

    Pereiro, Patricia; Romero, Alejandro; Díaz-Rosales, Patricia; Estepa, Amparo; Figueras, Antonio; Novoa, Beatriz

    2017-01-01

    With the exception of mammals, vertebrate erythrocytes are nucleated. Nevertheless, these cells are usually considered as mere carriers of hemoglobin. In this work, however, we describe for the first time an unrecognized role of teleost red blood cells (RBCs). We found that Nk-lysin (Nkl), an antimicrobial peptide produced by NK-cells and cytotoxic T-lymphocytes, was also expressed in flatfish turbot (Scophthalmus maximus) erythrocytes. Although the antiviral role of Nkl remains to be elucidated, we found a positive correlation between the transcription of nkl and the resistance to an infection with Rhabdovirus in a teleost fish. Surprisingly, Nkl was found to be present in the autophagolysosomes of erythrocytes, and therefore this higher resistance provided by Nkl could be related to autophagy. The organelles of RBCs are degraded through autophagy during the maturation process of these cells. In this work, we observed that the blockage of autophagy increased the replication of viral hemorrhagic septicemia virus in nucleated teleost erythrocytes, which suggests that this mechanism may also be a key process in the defense against viruses in these cells. Nkl, which possesses membrane-perturbing ability and was affected by this modulation of RBC autophagy, could also participate in this process. For the first time, autophagy has been described not only as a life cycle event during the maturation of erythrocytes but also as a pivotal antiviral mechanism in nucleated erythrocytes. These results suggest a role of erythrocytes and Nkl in the antiviral immunity of fish and other vertebrates with nucleated RBCs.

  11. THE IMPORTANCE OF THE ERYTHROCYTES OSMOTIC FRAGILITY TEST PERFORMED IN CHILDREN WITH INDIRECT HYPERBILIRUB1NEMIA

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    Ivana Stojanović

    2005-07-01

    Full Text Available The osmotic fragility test of erythrocytes is useful in the diagnosis of different types of hereditary hemolytic anemias followed with hyperbilirubinemia. Hemolytic anemias, characterized by accelerated destruction of red blood cells, are usually the consequence of many metabolic abnormalities like cellular membrane defect, erythrocyte enzymes defect or hemoglobin abnormalities – hemoglobinopathies. The object of our study was to assess the relationship between osmotic fragility test of erythrocytes and severity of indirect hyperbilirubinemia in some inherited erythrocytes’ disorders. We did the osmotic fragility test of erythrocytes by using Dacie, s method with normal values of erythrocytes hemolysis between 0,48 to 0,34% NaCl (minimal to maximal hemolysis. In hereditary spherocytosis, fragility of erythrocytes was increased (min. at 0,50 % NaCl to max. 0,44 % NaCl . In the child with β- thalassemia and cycle cell anemia erythrocytes fragility was decreased (min . at 0,42 to max. 0,32 % NaCl, that is 0,40% min. of hemolysis and 0,34% max. hemolysis in the second case. In newborn infants with high levels of indirect bilirubin in serum as a cause of physiological jaundice, the osmotic fragility test was within a normal range. Our findings point out the diagnostic value of osmotic fragility test in assessing patients with the indirect hyperbilirubinemia. This simple and important diagnostic test can be performed in small laboratories.

  12. Breakdown of Phosphatidylserine Asymmetry Following Treatment of Erythrocytes with Lumefantrine

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    Kousi Alzoubi

    2014-02-01

    Full Text Available Background: Lumefantrine, a commonly used antimalarial drug, inhibits hemozoin formation in parasites. Several other antimalarial substances counteract parasitemia by triggering suicidal death or eryptosis of infected erythrocytes. Eryptosis is characterized by cell shrinkage and cell membrane scrambling leading to phosphatidylserine-exposure at the erythrocyte surface. Signaling involved in eryptosis include increase of cytosolic Ca2+-activity ([Ca2+]i, formation of ceramide, oxidative stress and/or activation of p38 kinase, protein kinase C (PKC, or caspases. The present study explored, whether lumefantrine stimulates eryptosis. Methods: Cell volume has been estimated from forward scatter, phosphatidylserine-exposure from annexin V binding, [Ca2+]i from Fluo3-fluorescence, reactive oxygen species from 2',7'-dichlorodihydrofluorescein-diacetate fluorescence, content of reduced glutathione (GSH from mercury orange fluorescence, and ceramide abundance from binding of fluorescent antibodies in flow cytometry. Results: A 48 h exposure to lumefantrine (3 µg/mL was followed by a significant increase of annexin-V-binding without significantly altering forward scatter, [Ca2+]i, ROS formation, reduced GSH, or ceramide abundance. The annexin-V-binding following lumefantrine treatment was not significantly modified by p38 kinase inhibitors SB203580 (2 μM and p38 Inh III (1 μM, PKC inhibitor staurosporine (1 µM or pancaspase inhibitor zVAD (1 or 10 µM. Conclusions: Lumefantrine triggers cell membrane scrambling, an effect independent from entry of extracellular Ca2+, ceramide formation, ROS formation, glutathione content, p38 kinase, PKC or caspases.

  13. Optical properties of biomimetic probes engineered from erythrocytes

    Science.gov (United States)

    Burns, Joshua M.; Saager, Rolf; Majaron, Boris; Jia, Wangcun; Anvari, Bahman

    2017-01-01

    Light-activated theranostic materials offer a potential platform for optical imaging and phototherapeutic applications. We have engineered constructs derived from erythrocytes, which can be doped with the FDA-approved near infrared (NIR) chromophore, indocyanine green (ICG). We refer to these constructs as NIR erythrocyte-mimicking transducers (NETs). Herein, we investigated the effects of changing the NETs mean diameter from micron- (≈4 μm) to nano- (≈90 nm) scale, and the ICG concentration utilized in the fabrication of NETs from 5 to 20 μM on the resulting absorption and scattering characteristics of the NETs. Our approach consisted of integrating sphere-based measurements of light transmittance and reflectance, and subsequent utilization of these measurements in an inverse adding-doubling algorithm to estimate the absorption (μ a) and reduced scattering (μ s‧) coefficients of these NETs. For a given NETs diameter, values of μ a increased over the approximate spectral band of 630-860 nm with increasing ICG concentration. Micron-sized NETs produced the highest peak value of μ a when using ICG concentrations of 10 and 20 μM, and showed increased values of μ s‧ as compared to nano-sized NETs. Spectral profiles of μ s‧ for these NETs showed a trend consistent with Mie scattering behavior for spherical objects. For all NETs investigated, changing the ICG concentration minimally affected the scattering characteristics. A Monte Carlo-based model of light distribution showed that the presence of these NETs enhanced the fluence levels within simulated blood vessels. These results provide important data towards determining the appropriate light dosimetry parameters for an intended light-based biomedical application of NETs.

  14. New insights on the regulation of the adenine nucleotide pool of erythrocytes in mouse models

    Science.gov (United States)

    O’Brien, William G.; Ling, Han Shawn; Lee, Cheng Chi

    2017-01-01

    The observation that induced torpor in non-hibernating mammals could result from an increased AMP concentration in circulation led our investigation to reveal that the added AMP altered oxygen transport of erythrocytes. To further study the effect of AMP in regulation of erythrocyte function and systemic metabolism, we generated mouse models deficient in key erythrocyte enzymes in AMP metabolism. We have previously reported altered erythrocyte adenine nucleotide levels corresponding to altered oxygen saturation in mice deficient in both CD73 and AMPD3. Here we further investigate how these Ampd3-/-/Cd73-/- mice respond to the administered dose of AMP in comparison with the control models of single enzyme deficiency and wild type. We found that Ampd3-/-/Cd73-/- mice are more sensitive to AMP-induced hypometabolism than mice with a single enzyme deficiency, which are more sensitive than wild type. A dose-dependent rightward shift of erythrocyte p50 values in response to increasing amounts of extracellular AMP was observed. We provide further evidence for the direct uptake of AMP by erythrocytes that is insensitive to dipyridamole, a blocker for ENT1. The uptake of AMP by the erythrocytes remained linear at the highest concentration tested, 10mM. We also observed competitive inhibition of AMP uptake by ATP and ADP but not by the other nucleotides and metabolites tested. Importantly, our studies suggest that AMP uptake is associated with an erythrocyte ATP release that is partially sensitive to inhibition by TRO19622 and Ca++ ion. Taken together, our study suggests a novel mechanism by which erythrocytes recycle and maintain their adenine nucleotide pool through AMP uptake and ATP release. PMID:28746349

  15. Dapsone hydroxylamine induces premature removal of human erythrocytes by membrane reorganization and antibody binding

    Science.gov (United States)

    Bordin, Luciana; Fiore, Cristina; Zen, Francesco; Coleman, Michael D; Ragazzi, Eugenio; Clari, Giulio

    2010-01-01

    BACKGROUND AND PURPOSE N-hydroxylation of dapsone leads to the formation of the toxic hydroxylamines responsible for the clinical methaemoglobinaemia associated with dapsone therapy. Dapsone has been associated with decreased lifespan of erythrocytes, with consequences such as anaemia and morbidity in patients treated with dapsone for malaria. Here, we investigated how dapsone and/or its hydroxylamine derivative (DDS-NHOH) induced erythrocyte membrane alterations that could lead to premature cell removal. EXPERIMENTAL APPROACH Erythrocytes from healthy donors were subjected to incubation with dapsone and DDS-NHOH for varying times and the band 3 protein tyrosine-phosphorylation process, band 3 aggregation, membrane alteration and IgG binding were all examined and compared with erythrocytes from two patients receiving dapsone therapy. KEY RESULTS The hydroxylamine derivative, but not dapsone (the parent sulphone) altered membrane protein interactions, leading both to aggregation of band 3 protein and to circulating autologous antibody binding, shown in erythrocytes from patients receiving dapsone therapy. The band 3 tyrosine-phosphorylation process can be used as a diagnostic system to monitor membrane alterations both in vitro, assessing concentration and time-dependent effects of DDS-NHOH treatment, and in vivo, evaluating erythrocytes from dapsone-treated patients, in resting or oxidatively stimulated conditions. CONCLUSIONS AND IMPLICATIONS DDS-NHOH-induced alterations of human erythrocytes can be directly monitored in vitro by tyrosine-phosphorylation level and formation of band 3 protein aggregates. The latter, together with antibody-mediated labelling of erythrocytes, also observed after clinical use of dapsone, may lead to shortening of erythrocyte lifespan. PMID:20662842

  16. Signal transduction pathways in erythrocyte nitric oxide metabolism under high fibrinogen levels

    Science.gov (United States)

    Saldanha, Carlota; Freitas, T.; Lopez de Almeida, J. P.; Silva-Herdade, A.

    2014-05-01

    Previous studies show that the fibrinogen molecule modulates the metabolism of nitric oxide (NO) in erythrocyte. The in vitro induced hiperfibrinogenemia interferes in the metabolism of the NO in the erythrocyte in dependence of the phosphorylation degree of the band 3. The soluble form of fibrinogen binds into CD47 protein present in the erythrocyte membrane. The soluble thrombomodulin is an inflammatory marker that binds to the erythrocyte CD47 in a site with a sequence peptide known as 4N1K. A study done in vitro shows that when hiperfibrinogenemia was induced in the presence of the peptide 4N1K agonist of CD47 it were observed variations in the efflux of NO from erythrocyte and an increase in the concentrations of GSNO, peroxinitrite, nitrite and nitrate of the erythrocytes. The aim of this work was to study the influence of the peptide 4N1K, on the metabolism of NO in the erythrocyte under high fibrinogen concentration and in the presence of inhibitors of the status of phosphorylation of protein band 3. In this in vitro study, whole blood samples were harvested from healthy subjects and NO, peroxynitrite, nitrite, nitrate and S-nitro-glutathione (GSNO) were determined in presence of 4N1K, calpeptine, Syk inhibitor and under high fibrinogen concentrations. The results obtained in erythrocytes under high fibrinogen levels when 4N1K is present with the Syk inhibitor or with calpeptine, showed in relation to the control samples increased significant concentrations of efflux of NO and of peroxynitrite, nitrite, nitrate and GSNO. In conclusion it was verified that in the in vitro model of hiperfibrinogenemia the peptide 4N1K, agonist of CD47, induces mobilization of NO in the erythrocyte in dependence of the status of phosphorylation of protein band 3.

  17. The Trw type IV secretion system of Bartonella mediates host-specific adhesion to erythrocytes.

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    Muriel Vayssier-Taussat

    2010-06-01

    Full Text Available Bacterial pathogens typically infect only a limited range of hosts; however, the genetic mechanisms governing host-specificity are poorly understood. The alpha-proteobacterial genus Bartonella comprises 21 species that cause host-specific intraerythrocytic bacteremia as hallmark of infection in their respective mammalian reservoirs, including the human-specific pathogens Bartonella quintana and Bartonella bacilliformis that cause trench fever and Oroya fever, respectively. Here, we have identified bacterial factors that mediate host-specific erythrocyte colonization in the mammalian reservoirs. Using mouse-specific Bartonella birtlesii, human-specific Bartonella quintana, cat-specific Bartonella henselae and rat-specific Bartonella tribocorum, we established in vitro adhesion and invasion assays with isolated erythrocytes that fully reproduce the host-specificity of erythrocyte infection as observed in vivo. By signature-tagged mutagenesis of B. birtlesii and mutant selection in a mouse infection model we identified mutants impaired in establishing intraerythrocytic bacteremia. Among 45 abacteremic mutants, five failed to adhere to and invade mouse erythrocytes in vitro. The corresponding genes encode components of the type IV secretion system (T4SS Trw, demonstrating that this virulence factor laterally acquired by the Bartonella lineage is directly involved in adherence to erythrocytes. Strikingly, ectopic expression of Trw of rat-specific B. tribocorum in cat-specific B. henselae or human-specific B. quintana expanded their host range for erythrocyte infection to rat, demonstrating that Trw mediates host-specific erythrocyte infection. A molecular evolutionary analysis of the trw locus further indicated that the variable, surface-located TrwL and TrwJ might represent the T4SS components that determine host-specificity of erythrocyte parasitism. In conclusion, we show that the laterally acquired Trw T4SS diversified in the Bartonella lineage

  18. Bypassing adverse injection reactions to nanoparticles through shape modification and attachment to erythrocytes

    Science.gov (United States)

    Wibroe, Peter Popp; Anselmo, Aaron C.; Nilsson, Per H.; Sarode, Apoorva; Gupta, Vivek; Urbanics, Rudolf; Szebeni, Janos; Hunter, Alan Christy; Mitragotri, Samir; Mollnes, Tom Eirik; Moghimi, Seyed Moein

    2017-07-01

    Intravenously injected nanopharmaceuticals, including PEGylated nanoparticles, induce adverse cardiopulmonary reactions in sensitive human subjects, and these reactions are highly reproducible in pigs. Although the underlying mechanisms are poorly understood, roles for both the complement system and reactive macrophages have been implicated. Here, we show the dominance and importance of robust pulmonary intravascular macrophage clearance of nanoparticles in mediating adverse cardiopulmonary distress in pigs irrespective of complement activation. Specifically, we show that delaying particle recognition by macrophages within the first few minutes of injection overcomes adverse reactions in pigs using two independent approaches. First, we changed the particle geometry from a spherical shape (which triggers cardiopulmonary distress) to either rod- or disk-shape morphology. Second, we physically adhered spheres to the surface of erythrocytes. These strategies, which are distinct from commonly leveraged stealth engineering approaches such as nanoparticle surface functionalization with poly(ethylene glycol) and/or immunological modulators, prevent robust macrophage recognition, resulting in the reduction or mitigation of adverse cardiopulmonary distress associated with nanopharmaceutical administration.

  19. The Effects of Electromagnetic Fields Generated from 1800 MHz Cell Phones on Erythrocyte Rheological Parameters and Zinc Level in Rats

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    Ümit Divrikli

    2012-06-01

    Full Text Available Objective: The aim of this study was to investigate the effects of the electromagnetic field generated from the 1800 MHz radiofrequency radiation (EF on erythrocyte rheological parameters and erythrocyte zinc levels. Material and Methods: Twenty-four male Wistar Albino rats were randomly grouped as follows: 1 two control groups and 2 study groups: i Group A: EF exposed group (2.5 h/day for 30 days, the phone on stand-by, and ii Group B: EF exposed group (2.5 min/day for 30 days, the phone ringing in silent mode. At the end of the experimental period erythrocyte rheological parameters such as erythrocyte deformability and aggregation were determined by an ectacytometer. Erythrocyte zinc level, which affects hemorheological parameters, was also measured by atomic absorption spectrophotometer. Results: Erythrocyte deformability was decreased in both study groups but the decrease in group A was not statistically significant. Exposure to EF did not have any significant effect on erythrocyte aggregation. On the other hand, erythrocyte zinc level was significantly reduced in both study groups. Conclusion: Exposure to EF may have decreased tissue oxygenation due to reduced erythrocyte deformability. Decrease in erythrocyte zinc level may have caused the impairment in erythrocyte deformability.

  20. The Effects of Electromagnetic Fields Generated from 1800 MHz Cell Phones on Erythrocyte Rheological Parameters and Zinc Level in Rats.

    Science.gov (United States)

    Erken, Gülten; Küçükatay, Melek Bor; Turgut, Sebahat; Erken, Haydar Ali; Cömlekçi, Selçuk; Divrikli, Umit; Genç, Osman

    2012-06-01

    The aim of this study was to investigate the effects of the electromagnetic field generated from the 1800 MHz radiofrequency radiation (EF) on erythrocyte rheological parameters and erythrocyte zinc levels. Twenty-four male Wistar Albino rats were randomly grouped as follows: 1) two control groups and 2) study groups: i) Group A: EF exposed group (2.5 h/day for 30 days, the phone on stand-by), and ii) Group B: EF exposed group (2.5 min/day for 30 days, the phone ringing in silent mode). At the end of the experimental period erythrocyte rheological parameters such as erythrocyte deformability and aggregation were determined by an ectacytometer. Erythrocyte zinc level, which affects hemorheological parameters, was also measured by atomic absorption spectrophotometer. Erythrocyte deformability was decreased in both study groups but the decrease in group A was not statistically significant. Exposure to EF did not have any significant effect on erythrocyte aggregation. On the other hand, erythrocyte zinc level was significantly reduced in both study groups. Exposure to EF may have decreased tissue oxygenation due to reduced erythrocyte deformability. Decrease in erythrocyte zinc level may have caused the impairment in erythrocyte deformability.

  1. Impairment of Barrier Properties of Erythrocyte Membranes Caused by Low Temperatures is a Result of Disorganization of Hemoglobin Supramolecular Structure.

    Science.gov (United States)

    Gulevskvy, A K; Repin, N V; Schenvavsky, I I

    The antecedence of impairment of plasmatic membrane structure and functions forms the basis of the dominative concept about mechanisms of cell cryoinjuries. A role of alterations of hemoglobin supramolecular structure in erythrocytes remains unclear. Comparison of continuity of membranes of native erythrocytes and resealed ghosts after freeze-thawing with a cryoprotectant at a low concentration (4%). Cryoresistance of native erythrocytes and resealed ghosts with and without low concentrations of cryoprotectants (4% glycerol) was compared according to egress of the following markers: hemoglobin, 14С-sucrose and K+ as well as by scanning electron microscopy. It was found that resealed erythrocyte ghosts, where hemoglobin content was 4-5 times lower than in erythrocytes, were much more cryoresistant than native erythrocytes, which was especially noticeable when a low concentration of cryoprotectant (4% glycerol) was used. These data confirm an earlier proposed hypothesis on the role of supramolecular hemoglobin structure in cryoinjury mechanisms of erythrocytes.

  2. In vitro studies of graphene oxide reinforced hydroxyapatite nanobiocomposite on human erythrocytes

    Science.gov (United States)

    Radha, G.; Rohith Vinod, K.; Venkatesan, Balaji; Vellaichamy, Elangovan; Balakumar, S.

    2017-05-01

    We report the interaction of graphene oxide reinforced hydroxyapatite (GO-HAp) nanocomposites with human erythrocytes. The hemocompatibility of GO-HAp found to be superior as compared to the pristine graphene oxide. It is found that the HAp nanoparticles on GO decrease the disruption of erythrocytes by minimizing the exposure of oxygen groups to phosphatidylcholine surface of erythrocyte membrane and it enhances hemocompatibility. Further, it is also found that the graphene oxide reinforced HAp nanobiocomposite enhances the metabolic activity of osteoblasts-like cells by promoting cell proliferation.

  3. Encapsulation of interleukin-2 in murine erythrocytes and subsequent deposition in mice receiving a subcutaneous injection

    Energy Technology Data Exchange (ETDEWEB)

    DeLoach, J.R.; Andrews, K.; Sheffield, C.L.

    1988-04-01

    Radiolabeled recombinant human interleukin-2 (IL-2) was successfully encapsulated in both mouse and sheep erythrocytes. Of the added IL-2, 70% was recovered bound to or encapsulated within the carrier cells. Erythrocytes containing IL-2 were stable in vitro and most of the IL-2 remained associated with the cells following a 16-h incubation at 37 degrees C. When carrier erythrocytes containing IL-2 were injected subcutaneously into mice, intact (/sup 35/S)IL-2 was detectable in a number of tissues 3 days after injection.

  4. Association of aggressive periodontitis with reduced erythrocyte counts and reduced hemoglobin levels.

    Science.gov (United States)

    Anand, P S; Sagar, D K; Ashok, S; Kamath, K P

    2014-12-01

    Studies have shown that erythrocyte counts and hemoglobin levels are reduced in patients with chronic periodontitis, suggesting that this condition may be associated with anemia of chronic disease. Although increased leukocyte counts have been reported in aggressive periodontitis, very little is known about the effects of aggressive periodontitis on erythrocyte counts. The present study was undertaken to determine whether generalized aggressive periodontitis is associated with reduced erythrocyte counts and reduced hemoglobin levels. The present study was conducted as a case-control study in which 64 patients with generalized aggressive periodontitis were categorized as cases and 58 periodontally healthy individuals were categorized as controls. Erythrocyte parameters (such as erythrocyte count, hemoglobin concentration, and hematocrit and erythrocyte indices) and clinical parameters (such as gingival index, plaque index, probing depth, clinical attachment level and percentage of severe sites) were recorded. Significant differences were observed between cases and controls in mean erythrocyte count (4.45 ± 0.6 × 10(6) erythrocytes/μL and 4.78 ± 0.56 × 10(6) erythrocytes/μL respectively, p = 0.002) and hemoglobin level (12.43 ± 1.83 g/dL and 13.53 ± 1.64 g/dL, respectively, p = 0.001). Other erythrocyte parameters, such as hematocrit, mean corpuscular volume and mean corpuscular hemoglobin, were also significantly lower among cases compared with controls. Logistic regression analyses showed that generalized aggressive periodontitis was significantly associated with lower erythrocyte counts ( p = 0.032) and a lower hemoglobin concentration ( p = 0.017). The findings of the present study suggest that patients with generalized aggressive periodontitis tend to have lower erythrocyte counts and lower hemoglobin levels compared with periodontally healthy controls. This suggests that generalized aggressive periodontitis, like chronic

  5. Phase measurements of erythrocytes affected by metal ions with quantitative interferometric microscopy

    Science.gov (United States)

    Wang, Shouyu; Yan, Keding; Shan, Yanke; Xu, Mingfei; Liu, Fei; Xue, Liang

    2015-12-01

    Erythrocyte morphology is an important factor in disease diagnosis, however, traditional setups as microscopes and cytometers cannot provide enough quantitative information of cellular morphology for in-depth statistics and analysis. In order to capture variations of erythrocytes affected by metal ions, quantitative interferometric microscopy (QIM) is applied to monitor their morphology changes. Combined with phase retrieval and cell recognition, erythrocyte phase images, as well as phase area and volume, can be accurately and automatically obtained. The research proves that QIM is an effective tool in cellular observation and measurement.

  6. Identification of novel genetic determinants of erythrocyte membrane fatty acid composition among Greenlanders

    DEFF Research Database (Denmark)

    Andersen, Mette Korre; Jørsboe, Emil; Sandholt, Camilla Helene

    2016-01-01

    the understanding of the mechanisms and pathways involved in regulation of FA tissue levels, by identifying genetic loci associated with inter-individual differences in erythrocyte membrane FA levels. We assessed the levels of 22 FAs in the phospholipid fraction of erythrocyte membranes from 2,626 Greenlanders.......181), p = 2.8x10-4). In conclusion, we have identified novel genetic determinants of FA composition in phospholipids in erythrocyte membranes, and have shown examples of links between genetic variants associated with altered FA membrane levels and changes in metabolic traits....

  7. Method for Determining Erythrocyte Surface Area by Polarization and Nephelometric Measurements

    Science.gov (United States)

    Kugeiko, M. M.; Smunev, D. A.

    2016-01-01

    We propose a fast method for determining the surface area and volume of erythrocytes in the biconcave-discoid shape, based on establishing regression relations between the parameters to be determined and the angular polarization coefficients P(Θ) and scattering indicatrix σ(Θ). We have shown that using σ(Θ) for angles 6° and 17°, P(Θ) for angles 81° and 119° lets us determine the surface area of the erythrocytes within ≈1% and the volume of the erythrocytes within ≈2%.

  8. Occupational cadmium exposure-associated oxidative stress and erythrocyte fragility among jewelry workers in India.

    Science.gov (United States)

    Moitra, Subhabrata; Brashier, Bill B; Sahu, Subhashis

    2014-09-01

    Cadmium-induced pulmonary and renal target organ effects are well-established although its association with oxidative stress and associated hematological effects for human toxicity remain understudied. In a population of cadmium-exposed male jewelry manufacturing workers (n = 32) and referents without direct exposure (n = 21), all with urinary cadmium quantification, we measured plasma antioxidant enzymes (catalase, superoxide dismutase), lipid peroxidation (malondialdehyde), erythrocyte fragility, and surface irregularity of the erythrocyte membrane. Compared to referents, exposed workers manifested significantly lower plasma antioxidant enzymes, and increased malondialdehyde and erythrocyte fragility (for all, P toxicity. © 2014 Wiley Periodicals, Inc.

  9. ASSESSMENT OF ERYTHROCYTE PERIPHERAL BLOOD AND ACTIVITY OF HEMOST ASIS IN PATIENTS WITH CER VICAL CANCER

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    N. I. Stuklov

    2016-01-01

    Full Text Available Despite the availability and informative value of methods that facilitate the diagnosis, cervical cancer (CC does not lose its leading position as one of the most common cancers of the reproductive system in women worldwide. High prevalence of anemia and thrombotic complications in this group determines not only the quality of life of patients, but the outcome of the underlying disease. The purpose of the study was to determine the patterns of change in erythrocyte of peripheral blood and the state of vascular-platelet and coagulation hemostasis in patients with cervical cancer depending on the stage of disease and histological variant of the tumor.Materials and methods. We investigated the performance of erythron, thrombocytic and coagulation hemostasis in 74 patients with cervical cancer (mean age 46,49 ± 11,78 years. Blood analysis was performed in the initial evaluation of patients in the prehospital phase.Results. It is proved that the spread of the tumor outside the cervix exerts a systemic influence on hematopoiesis, hemostasis, significantly increasing the risk of venous thromboembolism and hematogenous dissemination of the disease (metastasis. In the case of adenocarcinoma and dimorphic (glandular-squamous cervical cancer we proved the significant increase in soluble fibrin-monomer complexes, fibrinogen, and with glandular-squamous-cell cervical cancer and hypercoagulability (decrease thrombin time, which requires mandatory and differentiated prevention of venous thromboembolism even in the early stages of these morphological variants of the disease.Conclusions. Cervical cancer has a systemic effect on the blood and hemostasis. A statistically significant decrease in the concentration of hemoglobin and increased erythrocyte sedimentation rate is determined in the second stage of the disease. The increase in the prevalence of cervical cancer and the presence of glandular component in the morphological

  10. Dynamic subcellular localization of isoforms of the folate pathway enzyme serine hydroxymethyltransferase (SHMT through the erythrocytic cycle of Plasmodium falciparum

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    Mitchell Sarah L

    2010-12-01

    Full Text Available Abstract Background The folate pathway enzyme serine hydroxymethyltransferase (SHMT converts serine to glycine and 5,10-methylenetetrahydrofolate and is essential for the acquisition of one-carbon units for subsequent transfer reactions. 5,10-methylenetetrahydrofolate is used by thymidylate synthase to convert dUMP to dTMP for DNA synthesis. In Plasmodium falciparum an enzymatically functional SHMT (PfSHMTc and a related, apparently inactive isoform (PfSHMTm are found, encoded by different genes. Here, patterns of localization of the two isoforms during the parasite erythrocytic cycle are investigated. Methods Polyclonal antibodies were raised to PfSHMTc and PfSHMTm, and, together with specific markers for the mitochondrion and apicoplast, were employed in quantitative confocal fluorescence microscopy of blood-stage parasites. Results As well as the expected cytoplasmic occupancy of PfSHMTc during all stages, localization into the mitochondrion and apicoplast occurred in a stage-specific manner. Although early trophozoites lacked visible organellar PfSHMTc, a significant percentage of parasites showed such fluorescence during the mid-to-late trophozoite and schizont stages. In the case of the mitochondrion, the majority of parasites in these stages at any given time showed no marked PfSHMTc fluorescence, suggesting that its occupancy of this organelle is of limited duration. PfSHMTm showed a distinctly more pronounced mitochondrial location through most of the erythrocytic cycle and GFP-tagging of its N-terminal region confirmed the predicted presence of a mitochondrial signal sequence. Within the apicoplast, a majority of mitotic schizonts showed a marked concentration of PfSHMTc, whose localization in this organelle was less restricted than for the mitochondrion and persisted from the late trophozoite to the post-mitotic stages. PfSHMTm showed a broadly similar distribution across the cycle, but with a distinctive punctate accumulation towards

  11. Cytotoxic effect of poly-dispersed single walled carbon nanotubes on erythrocytes in vitro and in vivo.

    Science.gov (United States)

    Sachar, Sumedha; Saxena, Rajiv K

    2011-01-01

    Single wall Carbon Nanotubes (SWCNTs) are hydrophobic and do not disperse in aqueous solvents. Acid functionalization of SWCNTs results in attachment of carboxy and sulfonate groups to carbon atoms and the resulting acid functionalized product (AF-SWCNTs) is negatively charged and disperses easily in water and buffers. In the present study, effect of AF-SWCNTs on blood erythrocytes was examined. Incubation of mouse erythrocytes with AF-SWCNTs and not with control SWCNTs, resulted in a dose and time dependent lysis of erythrocyte. Using fluorescence tagged AF-SWCNTs, binding of AF-SWCNTs with erythrocytes could be demonstrated. Confocal microscopy results indicated that AF-SWCNTs could enter the erythrocytes. Treatment with AF-SWCNTs resulted in exposure of hydrophobic patches on erythrocyte membrane that is indicative of membrane damage. A time and dose dependent increase in externalization of phosphatidylserine on erythrocyte membrane bilayer was also found. Administration of AF-SWCNTs through intravenous route resulted in a transient anemia as seen by a sharp decline in blood erythrocyte count accompanied with a significant drop in blood haemoglobin level. Administration of AF-SWCNTs through intratracheal administration also showed significant decline in RBC count while administration through other routes (gavage and intra-peritoneal) was not effective. By using a recently developed technique of a two step in vivo biotinylation of erythrocytes that enables simultaneous enumeration of young (age 40 days) erythrocytes in mouse blood, it was found that the in vivo toxic effect of AF-SWCNTs was more pronounced on older subpopulation of erythrocytes. Subpopulation of old erythrocytes fell after treatment with AF-SWCNTs but recovered by third day after the intravenous administration of AF-SWCNTs. Taken together our results indicate that treatment with AF-SWCNTs results in acute membrane damage and eventual lysis of erythrocytes. Intravenous administration of AF

  12. Enhanced suicidal erythrocyte death in mice carrying a loss-of-function mutation of the adenomatous polyposis coli gene

    Science.gov (United States)

    Qadri, Syed M; Mahmud, Hasan; Lang, Elisabeth; Gu, Shuchen; Bobbala, Diwakar; Zelenak, Christine; Jilani, Kashif; Siegfried, Alexandra; Föller, Michael; Lang, Florian

    2012-01-01

    Abstract Loss-of-function mutations in human adenomatous polyposis coli (APC) lead to multiple colonic adenomatous polyps eventually resulting in colonic carcinoma. Similarly, heterozygous mice carrying defective APC (apcMin/+) suffer from intestinal tumours. The animals further suffer from anaemia, which in theory could result from accelerated eryptosis, a suicidal erythrocyte death triggered by enhanced cytosolic Ca2+ activity and characterized by cell membrane scrambling and cell shrinkage. To explore, whether APC-deficiency enhances eryptosis, we estimated cell membrane scrambling from annexin V binding, cell size from forward scatter and cytosolic ATP utilizing luciferin–luciferase in isolated erythrocytes from apcMin/+ mice and wild-type mice (apc+/+). Clearance of circulating erythrocytes was estimated by carboxyfluorescein-diacetate-succinimidyl-ester labelling. As a result, apcMin/+ mice were anaemic despite reticulocytosis. Cytosolic ATP was significantly lower and annexin V binding significantly higher in apcMin/+ erythrocytes than in apc+/+ erythrocytes. Glucose depletion enhanced annexin V binding, an effect significantly more pronounced in apcMin/+ erythrocytes than in apc+/+ erythrocytes. Extracellular Ca2+ removal or inhibition of Ca2+ entry with amiloride (1 mM) blunted the increase but did not abrogate the genotype differences of annexin V binding following glucose depletion. Stimulation of Ca2+-entry by treatment with Ca2+-ionophore ionomycin (10 μM) increased annexin V binding, an effect again significantly more pronounced in apcMin/+ erythrocytes than in apc+/+ erythrocytes. Following retrieval and injection into the circulation of the same mice, apcMin/+ erythrocytes were more rapidly cleared from circulating blood than apc+/+ erythrocytes. Most labelled erythrocytes were trapped in the spleen, which was significantly enlarged in apcMin/+ mice. The observations point to accelerated eryptosis and subsequent clearance of apcMin/+ erythrocytes

  13. Compound heterozygosity with a novel S222N GALT mutation leads to atypical galactosemia with loss of GALT activity in erythrocytes but little evidence of clinical disease

    Directory of Open Access Journals (Sweden)

    Benjamin Cocanougher

    2015-03-01

    Full Text Available Galactosemia is an inborn error of galactose metabolism caused by mutations in the GALT gene. Though early detection and galactose restriction prevent severe liver disease, affected individuals have persistently elevated biomarkers and often neuro-developmental symptoms. We present a teenage compound heterozygote for a known pathogenic mutation (H132Q and a novel variant of unknown significance (S222N, with nearly absent erythrocyte GALT enzyme activity but normal biomarkers and only mild anxiety despite diet non-adherence. This case is similar to a previously reported S135L mutation. In this report we investigate the novel S222N variant and critically evaluate a clinically puzzling case.

  14. Interaction of erythrocyte eicosapentaenoic acid and physical activity predicts reduced risk of mild cognitive impairment.

    Science.gov (United States)

    Street, Steven John; Parletta, Natalie; Milte, Catherine; Sullivan, Karen; Hills, Andrew P; Buckley, Jonathan; Howe, Peter

    2015-01-01

    To evaluate relationships between self-reported physical activity, proportions of long-chain omega-3 polyunsaturated fatty acids (LCn3) in erythrocyte content (percentage of total fatty acids) and risk of mild cognitive impairment (MCI) in older adults. A cross-sectional study was conducted. Community-dwelling male and female (n = 84) participants over the age of 65 years with and without MCI were tested for erythrocyte proportions of the LCn3s eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Physical activity was measured using a validated questionnaire. The interaction between erythrocyte EPA, but not DHA, and increased physical activity was associated with increased odds of a non-MCI classification. An interaction between physical activity and erythrocyte EPA content (percentage of fatty acids) significantly predicted MCI status in older adults. Randomised control trials are needed to examine the potential for supplementation with EPA in combination with increased physical activity to mitigate the risk of MCI in ageing adults.

  15. Protein-stimulated exchange of phosphatidylcholine between intact erythrocytes and various membrane systems

    NARCIS (Netherlands)

    Meer, G. van; Lange, L.G.; Kamp, J.A.F. op den; Deenen, L.L.M. van

    1980-01-01

    Phosphatidylcholine specific exchange protein from beef liver was found to catalyze the exchange of phosphatidylcholine between intact rat and human erythrocytes and various artificial membranes. Both multilamellar liposomes and single bilayer vesicles prepared from egg lecithin, cholesterol and

  16. Cyclin D3 coordinates the cell cycle during differentiation to regulate erythrocyte size and number.

    Science.gov (United States)

    Sankaran, Vijay G; Ludwig, Leif S; Sicinska, Ewa; Xu, Jian; Bauer, Daniel E; Eng, Jennifer C; Patterson, Heide Christine; Metcalf, Ryan A; Natkunam, Yasodha; Orkin, Stuart H; Sicinski, Piotr; Lander, Eric S; Lodish, Harvey F

    2012-09-15

    Genome-wide association studies (GWASs) have identified a genetic variant of moderate effect size at 6p21.1 associated with erythrocyte traits in humans. We show that this variant affects an erythroid-specific enhancer of CCND3. A Ccnd3 knockout mouse phenocopies these erythroid phenotypes, with a dramatic increase in erythrocyte size and a concomitant decrease in erythrocyte number. By examining human and mouse primary erythroid cells, we demonstrate that the CCND3 gene product cyclin D3 regulates the number of cell divisions that erythroid precursors undergo during terminal differentiation, thereby controlling erythrocyte size and number. We illustrate how cell type-specific specialization can occur for general cell cycle components-a finding resulting from the biological follow-up of unbiased human genetic studies.

  17. Loading of erythrocyte membrane with pentacyclic triterpenes inhibits Plasmodium falciparum invasion

    DEFF Research Database (Denmark)

    Ziegler, Hanne L; Staalsø, Trine; Jaroszewski, Jerzy W

    2006-01-01

    Lupeol and betulinic acid inhibit the proliferation of Plasmodium falciparum parasites by inhibition of the invasion of merozoites into erythrocytes. This conclusion is based on experiments employing parasite cultures synchronized by magnetic cell sorting (MACS). Identical inhibitory effects were...

  18. Interactions of the antiviral and antiparkinson agent amantadine with lipid membranes and human erythrocytes.

    Science.gov (United States)

    Suwalsky, Mario; Jemiola-Rzeminska, Malgorzata; Altamirano, Mariella; Villena, Fernando; Dukes, Nathan; Strzalka, Kazimierz

    2015-07-01

    Aimed to better understand the molecular mechanisms of its interactions with cell membranes, human erythrocyte and molecular models of the red cell membrane were utilized. The latter consisted of bilayers of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), representative of phospholipid classes located in the outer and inner monolayers of the human erythrocyte membrane, respectively. The capacity of amantadine to perturb the bilayer structures of DMPC and DMPE was evaluated by X-ray diffraction, fluorescence spectroscopy and differential scanning calorimetry (DSC). In an attempt to further elucidate its effects on cell membranes, the present work also examined amantadine influence on the morphology of intact human erythrocytes by means of scanning electron microscopy (SEM). Results indicated that amantadine induced morphological changes to human erythrocytes and interacted in a concentration-dependent manner with DMPC bilayers in contrast to DMPE that was hardly affected by the presence of the drug. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Local defects in the nanostructure of the membrane of erythrocytes upon ionizing radiation of blood

    Science.gov (United States)

    Kozlova, E. K.; Sergunova, V. A.; Krasavin, E. A.; Boreyko, A. V.; Zavialova, A. V.; Kozlov, A. P.; Chernysh, A. M.

    2016-01-01

    The purpose of the study is to investigate local topological defects in the erythrocyte membranes resulting from the ultraviolet (UV) radiation of blood in vitro. Biological effects in the erythrocytes after exposure to UV radiation at a wavelength of 254 nm are equivalent to those after γ radiation. It has been shown that oxidative processes developing in a suspension upon UV radiation result in the disruption of the nanostructure of the membranes of erythrocytes. In the experiments, typical topological defects in the membrane nanostructure were observed. The parameters of the defects differed from the characteristics of the nanostructure of the control cell membrane without irradiation. The characteristic dimensions of the topological defects are commensurate with the size of the spectrin matrix. As a result of the exposure to the UV radiation, polymorphism of the erythrocytes was observed.

  20. Plasmodium falciparum normocyte binding protein (PfNBP-1) peptides bind specifically to human erythrocytes.

    Science.gov (United States)

    Valbuena, John Jairo; Vera, Ricardo; García, Javier; Puentes, Alvaro; Curtidor, Hernando; Ocampo, Marisol; Urquiza, Mauricio; Rivera, Zuly; Guzmán, Fanny; Torres, Elizabeth; Patarroyo, Manuel Elkin

    2003-07-01

    Plasmodium falciparum normocyte binding protein-1 (PfNBP-1), a Plasmodium vivax RBP-1 orthologue is expressed in the apical merozoite area. PfNBP-1 binds directly to human erythrocyte membrane in a sialic acid-dependent but trypsin-resistant way. Erythrocyte binding assays were done with synthetic peptides covering the sequence reported as PfNBP-1. Two specific erythrocyte high activity binding peptides were found: 101VFINDLDTYQYEYFYEWNQ(120), peptide 26332, and 181NTKETYLKELNKKKMLQNKK(200), peptide 26336. These two peptides' binding was saturable and presenting nanomolar affinity constants. The critical binding residues (those residues underlined and highlighted in bold) were determined by competition assays with glycine-scan analogue peptides. These peptides were able to block merozoite in vitro invasion of erythrocytes.

  1. Role of Ca2+-activated K+ channels in human erythrocyte apoptosis

    National Research Council Canada - National Science Library

    Philipp A. Lang; Stefanie Kaiser; Swetlana Myssina; Thomas Wieder; Florian Lang; Stephan M. Huber

    2003-01-01

    Exposure of erythrocytes to the Ca2+ ionophore ionomycin has recently been shown to induce cell shrinkage, cell membrane blebbing, and breakdown of phosphatidylserine asymmetry, all features typical of apoptosis of nucleated cells...

  2. New Insight into Erythrocyte through In Vivo Surface-Enhanced Raman Spectroscopy

    DEFF Research Database (Denmark)

    Brazhe, Nadezda A.; Abdali, Salim; Brazhe, Alexey R.

    2009-01-01

    erythrocyte: submembrane and cytosolic hemoglobin (Hb(sm) and Hb(c)). We show that the conformation of Hbsm differs from the conformation of Hbc. This finding has an important application, as the comparative study of Hbsm and Hbc could be successfully used in biomedical research and diagnostic tests....... containing erythrocytes in their normal physiological environment in a mixture of colloid solution with silver nanoparticles and the procedure for the optimization of SERS conditions to achieve high signal enhancement without affecting the properties of living erythrocytes. By means of three independent...... techniques, we demonstrate that under the proposed conditions a colloid solution of silver nanoparticles does not affect the properties of erythrocytes. For the first time to our knowledge, we describe how to use the SERS-RS approach to study two populations of hemoglobin molecules inside an intact living...

  3. Anemia in children with chronic renal failure Special attention erythrocyte indices and iron deficiency anemia

    National Research Council Canada - National Science Library

    Adi Suryanto B; Partini P Trihono; Agus Firmansyah

    2016-01-01

    ...), Jakarta, with special atten- tion in erythrocyte indices and iron deficiency anemia. Methods Cross-sectional descriptive study was carried out on patients with CRF and anemia in CMH since October 2003 to April 2004...

  4. Hepcidin is the major predictor of erythrocyte iron incorporation in anemic African children

    Science.gov (United States)

    Iron supplementation strategies in the developing world remain controversial owing to fears of exacerbating prevalent infectious diseases. Understanding the conditions in which iron will be absorbed and incorporated into erythrocytes is therefore important. We studied Gambian children with either po...

  5. A new method for culturing Plasmodium falciparum shows replication at the highest erythrocyte densities

    Science.gov (United States)

    Li, Tao; Glushakova, Svetlana; Zimmerberg, Joshua

    2003-01-01

    Plasmodium falciparum replicates poorly in erythrocyte densities greater than a hematocrit of 20%. A new method to culture the major malaria parasite was developed by using a hollow fiber bioreactor that preserves healthy erythrocytes at hematocrit up to 100%. P. falciparum replicated equally well at all densities studied. This method proved advantageous for large-scale preparation of parasitized erythrocytes (and potentially immunogens thereof), because high yields ( approximately 10(10) in 4 days) could be prepared with less cost and labor. Concomitantly, secreted proteins were concentrated by molecular sieving during culture, perhaps contributing to the parasitemic limit of 8%-12% with the 3D7 strain. The finding that P. falciparum can replicate at packed erythrocyte densities suggests that this system may be useful for study of the pathogenesis of fatal cerebral malaria, of which one feature is densely packed blood cells in brain microvasculature.

  6. Calibration of an electronic counter and pulse height analyzer for plotting erythrocyte volume spectra.

    Science.gov (United States)

    1963-03-01

    A simple technique is presented for calibrating an electronic system used in the plotting of erythrocyte volume spectra. The calibration factors, once obtained, apparently remain applicable for some time. Precise estimates of calibration factors appe...

  7. Effects of phenylpropanolamine (PPA) on in vitro human erythrocyte membranes and molecular models

    Energy Technology Data Exchange (ETDEWEB)

    Suwalsky, Mario, E-mail: msuwalsk@udec.cl [Faculty of Chemical Sciences, University of Concepcion, Concepcion (Chile); Zambrano, Pablo; Mennickent, Sigrid [Faculty of Pharmacy, University of Concepcion, Concepcion (Chile); Villena, Fernando [Faculty of Biological Sciences, University of Concepcion, Concepcion (Chile); Sotomayor, Carlos P.; Aguilar, Luis F. [Instituto de Quimica, Pontificia Universidad Catolica de Valparaiso, Valparaiso (Chile); Bolognin, Silvia [CNR-Institute for Biomedical Technologies, University of Padova, Padova (Italy)

    2011-03-18

    Research highlights: {yields} PPA is a common ingredient in cough-cold medication and appetite suppressants. {yields} Reports on its effects on human erythrocytes are very scarce. {yields} We found that PPA induced in vitro morphological changes to human erythrocytes. {yields} PPA interacted with isolated unsealed human erythrocyte membranes. {yields} PPA interacted with class of lipid present in the erythrocyte membrane outer monolayer. -- Abstract: Norephedrine, also called phenylpropanolamine (PPA), is a synthetic form of the ephedrine alkaloid. After reports of the occurrence of intracranial hemorrhage and other adverse effects, including several deaths, PPA is no longer sold in USA and Canada. Despite the extensive information about PPA toxicity, reports on its effects on cell membranes are scarce. With the aim to better understand the molecular mechanisms of the interaction of PPA with cell membranes, ranges of concentrations were incubated with intact human erythrocytes, isolated unsealed human erythrocyte membranes (IUM), and molecular models of cell membranes. The latter consisted in bilayers built-up of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), phospholipid classes present in the outer and inner monolayers of most plasmatic cell membranes, respectively. The capacity of PPA to perturb the bilayer structures of DMPC and DMPE was assessed by X-ray diffraction, DMPC large unilamellar vesicles (LUV) and IUM were studied by fluorescence spectroscopy, and intact human erythrocytes were observed by scanning electron microscopy (SEM). This study presents evidence that PPA affects human red cell membranes as follows: (a) in SEM studies on human erythrocytes it was observed that 0.5 mM PPA induced shape changes; (b) in IUM PPA induced a sharp decrease in the fluorescence anisotropy in the lipid bilayer acyl chains in a concentration range lower than 100 {mu}M; (c) X-ray diffraction studies showed that PPA in the 0.1-0.5 m

  8. Purification of the NF2 tumor suppressor protein from human erythrocytes.

    Science.gov (United States)

    Jindal, Hitesh K; Yoshinaga, Kazumi; Seo, Pil-Soo; Lutchman, Mohini; Dion, Patrick A; Rouleau, Guy A; Hanada, Toshihiko; Chishti, Athar H

    2006-11-01

    Neurofibromatosis type 2 (NF2) is an autosomal dominant disease predisposing individuals to the risk of developing tumors of cranial and spinal nerves. The NF2 tumor suppressor protein, known as Merlin/Schwanomin, is a member of the protein 4.1 superfamily that function as links between the cytoskeleton and the plasma membrane. Upon selective extraction of membrane-associated proteins from erythrocyte plasma membrane (ghosts) using low ionic strength solution, the bulk of NF2 protein remains associated with the spectrin-actin depleted inside-out-vesicles. Western blot analysis showed a approximately 70 kDa polypeptide in the erythrocyte plasma membrane. Furthermore, quantitative removal of NF2 protein from the inside-out-vesicles was achieved using 1.0 M potassium iodide, a treatment known to remove tightly-bound peripheral membrane proteins. These results suggest a novel mode of NF2 protein association with the erythrocyte membrane that is distinct from the known membrane interactions of protein 4.1. Based on these biochemical properties, several purification strategies were devised to isolate native NF2 protein from human erythrocyte ghosts. Using purified and recombinant NF2 protein as internal standards, we quantified approximately 41-65,000 molecules of NF2 protein per erythrocyte. We provide evidence for the presence of NF2 protein in the human erythrocyte membrane. The identification of NF2 protein in the human erythrocyte membrane will make it feasible to discover novel interactions of NF2 protein utilizing powerful techniques of erythrocyte biochemistry and genetics in mammalian cells.

  9. [The activity of adenosinetriphosphatase of erythrocytes in peripheral blood of patients with colorectal cancer].

    Science.gov (United States)

    Terekhina, N A; Zitta, D V; Subbotin, V M

    2005-05-01

    We studied the activity of whole ATPase, Mg2+ -ATPase and Na+, K+ -ATPase of peripheral blood erythrocytes in 68 patients with colorectal cancer before surgery and immediately after it and found such activity to be reduced. The low activity of Na+, K+ -ATPase of peripheral blood erythrocyte was shown as possible for use in prognosticating acute postoperative erosive-ulcerous lesions of the gastric tunic. Ozone therapy, if undertaken preoperatively, restores the ATPase activity.

  10. An Ensemble Rule Learning Approach for Automated Morphological Classification of Erythrocytes.

    Science.gov (United States)

    Maity, Maitreya; Mungle, Tushar; Dhane, Dhiraj; Maiti, A K; Chakraborty, Chandan

    2017-04-01

    The analysis of pathophysiological change to erythrocytes is important for early diagnosis of anaemia. The manual assessment of pathology slides is time-consuming and complicated regarding various types of cell identification. This paper proposes an ensemble rule-based decision-making approach for morphological classification of erythrocytes. Firstly, the digital microscopic blood smear images are pre-processed for removal of spurious regions followed by colour normalisation and thresholding. The erythrocytes are segmented from background image using the watershed algorithm. The shape features are then extracted from the segmented image to detect shape abnormality present in microscopic blood smear images. The decision about the abnormality is taken using proposed multiple rule-based expert systems. The deciding factor is majority ensemble voting for abnormally shaped erythrocytes. Here, shape-based features are considered for nine different types of abnormal erythrocytes including normal erythrocytes. Further, the adaptive boosting algorithm is used to generate multiple decision tree models where each model tree generates an individual rule set. The supervised classification method is followed to generate rules using a C4.5 decision tree. The proposed ensemble approach is precise in detecting eight types of abnormal erythrocytes with an overall accuracy of 97.81% and weighted sensitivity of 97.33%, weighted specificity of 99.7%, and weighted precision of 98%. This approach shows the robustness of proposed strategy for erythrocytes classification into abnormal and normal class. The article also clarifies its latent quality to be incorporated in point of care technology solution targeting a rapid clinical assistance.

  11. Influence of Cocoa Flavanols and Procyanidins on Free Radical-induced Human Erythrocyte Hemolysis

    Directory of Open Access Journals (Sweden)

    Qin Yan Zhu

    2005-01-01

    Full Text Available Cocoa can be a rich source of antioxidants including the flavan-3-ols, epicatechin and catechin, and their oligomers (procyanidins. While these flavonoids have been reported to reduce the rate of free radical-induced erythrocyte hemolysis in experimental animal models, little is known about their effect on human erythrocyte hemolysis. The major objective of this work was to study the effect of a flavonoid-rich cocoa beverage on the resistance of human erythrocytes to oxidative stress. A second objective was to assess the effects of select purified cocoa flavonoids, epicatechin, catechin, the procyanidin Dimer B2 and one of its major metabolites, 3ʹ-O-methyl epicatechin, on free radical-induced erythrocyte hemolysis in vitro. Peripheral blood was obtained from 8 healthy subjects before and 1, 2, 4 and 8 h after consuming a flavonoid-rich cocoa beverage that provided 0.25 g/kg body weight (BW, 0.375 or 0.50 g/kg BW of cocoa. Plasma flavanol and dimer concentrations were determined for each subject. Erythrocyte hemolysis was evaluated using a controlled peroxidation reaction. Epicatechin, catechin, 3ʹ-O-methyl epicatechin and (--epicatechin-(4β > 8epicatechin (Dimer B2 were detected in the plasma within 1 h after the consumption of the beverage. The susceptibility of erythrocytes to hemolysis was reduced significantly following the consumption of the beverages. The duration of the lag time, which reflects the capacity of cells to buffer free radicals, was increased. Consistent with the above, the purified flavonoids, epicatechin, catechin, Dimer B2 and the metabolite 3ʹ-O-methyl epicatechin, exhibited dose-dependent protection against AAPH-induced erythrocyte hemolysis at concentrations ranging from 2.5 to 20 μM. Erythrocytes from subjects consuming flavonoid-rich cocoa show reduced susceptibility to free radical-induced hemolysis (p < 0.05.

  12. Dynamic adhesion of eryptotic erythrocytes to endothelial cells via CXCL16/SR-PSOX.

    Science.gov (United States)

    Borst, Oliver; Abed, Majed; Alesutan, Ioana; Towhid, Syeda T; Qadri, Syed M; Föller, Michael; Gawaz, Meinrad; Lang, Florian

    2012-02-15

    Suicidal death of erythrocytes, or eryptosis, is characterized by cell shrinkage and cell membrane scrambling leading to phosphatidylserine exposure at the cell surface. Eryptosis is triggered by increase of cytosolic Ca2+ activity, which may result from treatment with the Ca2+ ionophore ionomycin or from energy depletion by removal of glucose. The present study tested the hypothesis that phosphatidylserine exposure at the erythrocyte surface fosters adherence to endothelial cells of the vascular wall under flow conditions at arterial shear rates and that binding of eryptotic cells to endothelial cells is mediated by the transmembrane CXC chemokine ligand 16 (CXCL16). To this end, human erythrocytes were exposed to energy depletion (for 48 h) or treated with the Ca2+ ionophore ionomycin (1 μM for 30 min). Phosphatidylserine exposure was quantified utilizing annexin-V binding, cell volume was estimated from forward scatter in FACS analysis, and erythrocyte adhesion to human vascular endothelial cells (HUVEC) was determined in a flow chamber model. As a result, both, ionomycin and glucose depletion, triggered eryptosis and enhanced the percentage of erythrocytes adhering to HUVEC under flow conditions at arterial shear rates. The adhesion was significantly blunted in the presence of erythrocyte phosphatidylserine-coating annexin-V (5 μl/ml), of a neutralizing antibody against endothelial CXCL16 (4 μg/ml), and following silencing of endothelial CXCL16 with small interfering RNA. The present observations demonstrate that eryptotic erythrocytes adhere to endothelial cells of the vascular wall in part by interaction of phosphatidylserine exposed at the erythrocyte surface with endothelial CXCL16.

  13. Reduced Ca2+ entry and suicidal death of erythrocytes in PDK1 hypomorphic mice.

    Science.gov (United States)

    Föller, Michael; Mahmud, Hasan; Koka, Saisudha; Lang, Florian

    2008-02-01

    The phosphoinositide-dependent kinase PDK1 is a key element in the phosphoinositol-3-kinase signalling pathway, which is involved in the regulation of ion channels, transporters, cell volume and cell survival. Eryptosis, the suicidal death of erythrocytes, is characterized by decrease in cell volume, cell membrane blebbing and phospholipids scrambling with phosphatidylserine exposure at the cell surface. Oxidative stress, osmotic shock or Cl- removal trigger eryptosis by activation of Ca2+-permeable cation channels and subsequent increase in cytosolic Ca2+ activity. To explore the impact of PDK1 for erythrocyte survival, eryptosis was analysed in hypomorphic mice (pdk1hm) expressing only some 25% of PDK1 and in their wild-type littermates (pdk1wt). Cell volume was estimated from forward scatter and phosphatidylserine exposure from annexin-V binding in fluorescence activated cell sorter analysis. Forward scatter was smaller in pdk1hm than in pdk1wt erythrocytes. Oxidative stress (100 microM tert-butylhydroperoxide), osmotic shock (+300 mM sucrose) and Cl- removal (replacement of Cl- with gluconate) all decreased forward scatter and increased the percentage of annexin-V-binding erythrocytes from both pdk1hm and pdk1wt mice. After treatment, the forward scatter was similar in both genotypes, but the percentage of annexin-V binding was significantly smaller in pdk1hm than in pdk1wt erythrocytes. According to Fluo-3 fluorescence, cytosolic Ca2+ activity was significantly smaller in pdk1hm than in pdk1wt erythrocytes. Treatment with Ca2+-ionophore ionomycin (1 microM) was followed by an increase in annexin-V binding to similar levels in pdk1hm and pdk1wt erythrocytes. The experiments reveal that PDK1 deficiency is associated with decreased Ca2+ entry into erythrocytes and thus with blunted eryptotic effects of oxidative stress, osmotic shock and Cl- removal.

  14. Atomic force microscopy of swelling and hardening of intact erythrocytes fixed on substrate

    Science.gov (United States)

    Khalisov, M. M.; Timoshchuk, K. I.; Ankudinov, A. V.; Timoshenko, T. E.

    2017-02-01

    Peak force measurements with the aid of atomic force microscopy are used to quantitatively map nanomechanical properties of intact erythrocytes of rats under conditions that are close to physiological conditions. Erythrocytes that are immobilized on the substrate preliminary processed using poly-L-lysine predominantly exhibit plane shape. However, cells may also exhibit stepwise transformation to semispherical objects with an increase in volume and hardening. Possible reasons for such transformations are discussed.

  15. Thyroid hormones and erythrocyte indices in a cohort of euthyroid older subjects.

    Science.gov (United States)

    Schindhelm, Roger K; ten Boekel, Edwin; Heima, Nathalie E; van Schoor, Natasja M; Simsek, Suat

    2013-04-01

    Hypothyroidism is associated with normocytic anaemia. Indeed, a limited number of studies have shown significant associations between free thyroxin (T4) and erythrocyte indices. These studies did not include vitamin B12, folic acid, iron and renal function in the analyses. We therefore studied the association between thyroid hormones and erythrocyte indices in a population-based cohort of older euthyroid subjects, with adjustment for major confounding parameters. Data, including thyroid hormones and erythrocyte indices, are from the Longitudinal Aging Study Amsterdam (LASA), an ongoing cohort study on predictors and consequences of changes in health in the ageing population in the Netherlands. Multivariable linear regression analyses were applied to study the cross-sectional associations between free T4, thyroid stimulating hormone (TSH) and erythrocyte indices (haemoglobin content, haematocrit, mean cell volume (MCV) and erythrocyte count) in a euthyroid sub-sample. The final models were adjusted for vitamin B12, folic acid, iron levels and renal function. In 708 euthyroid older subjects, an increase of 5pmol/L free T4 was associated with a mean increase of 0.12mmol/L or 0.19g/dL of haemoglobin, 0.068 10(12)/L erythrocytes and 0.006L/L haematocrit (P=0.007, P=0.005, P=0.001, respectively). Free T4 was not significantly associated with MCV (P>0.05). TSH appeared not to be associated with any of the erythrocyte indices (all P>0.05). In a cohort of older subjects, free T4, but not TSH, was associated with erythrocyte indices, confirming the role of thyroid hormones in the regulation of erythropoiesis. Copyright © 2012 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  16. Electrolyte content of serum, erythrocyte, kidney and heart tissue in salt induced hypertensive rats.

    Science.gov (United States)

    Mahboob, T; Mumtaz, M; Haleem, M A

    1996-01-01

    The effect of salt load on the systolic blood pressure (SBP) and electrolyte levels of serum, erythrocyte, kidney and heart tissue was studied in rats. NaCl treatment increased sodium (5.69 +/- 0.4 mmol/L p electrolyte levels of erythrocytes, serum, heart and kidney tissues in NaCl loaded rats may play a definite role in the development of salt induced hypertension.

  17. Concentration of selenium in plasma and erythrocytes during total parenteral nutrition in Crohn's disease.

    OpenAIRE

    Jacobson, S; Plantin, L O

    1985-01-01

    Plasma- and erythrocyte-selenium concentrations were determined in five consecutive patients with Crohn's disease given preoperative total parenteral nutrition - nil per os - for a mean period of 34 days per patient. No blood components were administered during the total parenteral nutrition. Before the total parenteral nutrition the plasma-selenium level and, to a less extent, the erythrocyte-selenium levels were below the reference values. After three weeks of total parenteral nutrition bot...

  18. Polyunsaturated Fatty Acid Levels in Maternal Erythrocytes of Japanese Women during Pregnancy and after Childbirth

    Science.gov (United States)

    Kawabata, Terue; Kagawa, Yasuo; Kimura, Fumiko; Miyazawa, Teruo; Saito, Shoji; Arima, Takahiro; Nakai, Kunihiko; Yaegashi, Nobuo

    2017-01-01

    Background: The transport of polyunsaturated fatty acids (PUFAs), such as arachidonic acid (ARA, 20:4n-6) and docosahexaenoic acid (DHA, 22:6n-3), to the fetus from maternal stores increases depending on the fetal requirements for PUFA during the last trimester of pregnancy. Therefore, maternal blood PUFA changes physiologically with gestational age. However, the changes in PUFA levels in maternal blood erythrocytes during pregnancy and after childbirth have not been fully investigated in a fish-eating population. Objective: To examine the changes of ARA and DHA levels in maternal erythrocytes with the progress of pregnancy and the relationship between maternal and umbilical cord erythrocyte PUFA levels in pregnant Japanese women who habitually eat fish and shellfish. Design: This study was performed as a part of the adjunct study of the Japan Environment and Children’s Study (JECS). The participants were 74 pregnant women. The maternal blood samples were collected at 27, 30, and 36 weeks of pregnancy, and 2 days and 1 month after delivery, and umbilical cord blood was collected at delivery. The fatty acid levels of erythrocytes in these blood samples were determined. Results: ARA and DHA levels in maternal erythrocytes tended to decrease with the progress of pregnancy. While the DHA level decreased further after delivery, the ARA level returned to the value at 27 weeks of pregnancy within 1 month after delivery. The n-3 and n-6 PUFA levels in maternal erythrocytes at 27, 30, and 36 weeks of pregnancy were significantly positively correlated with the corresponding fatty acid levels in umbilical cord erythrocytes. Conclusion: The present findings showed a significant change in erythrocyte PUFA levels during pregnancy and after childbirth in a fish-eating population. The PUFA levels of maternal blood after the second trimester may be a reliable marker for predicting PUFA levels in infants’ circulating blood. PMID:28272345

  19. Hematopoietic protein-1 regulates the actin membrane skeleton and membrane stability in murine erythrocytes.

    Directory of Open Access Journals (Sweden)

    Maia M Chan

    Full Text Available Hematopoietic protein-1 (Hem-1 is a hematopoietic cell specific member of the WAVE (Wiskott-Aldrich syndrome verprolin-homologous protein complex, which regulates filamentous actin (F-actin polymerization in many cell types including immune cells. However, the roles of Hem-1 and the WAVE complex in erythrocyte biology are not known. In this study, we utilized mice lacking Hem-1 expression due to a non-coding point mutation in the Hem1 gene to show that absence of Hem-1 results in microcytic, hypochromic anemia characterized by abnormally shaped erythrocytes with aberrant F-actin foci and decreased lifespan. We find that Hem-1 and members of the associated WAVE complex are normally expressed in wildtype erythrocyte progenitors and mature erythrocytes. Using mass spectrometry and global proteomics, Coomassie staining, and immunoblotting, we find that the absence of Hem-1 results in decreased representation of essential erythrocyte membrane skeletal proteins including α- and β- spectrin, dematin, p55, adducin, ankyrin, tropomodulin 1, band 3, and band 4.1. Hem1⁻/⁻ erythrocytes exhibit increased protein kinase C-dependent phosphorylation of adducin at Ser724, which targets adducin family members for dissociation from spectrin and actin, and subsequent proteolysis. Increased adducin Ser724 phosphorylation in Hem1⁻/⁻ erythrocytes correlates with decreased protein expression of the regulatory subunit of protein phosphatase 2A (PP2A, which is required for PP2A-dependent dephosphorylation of PKC targets. These results reveal a novel, critical role for Hem-1 in the homeostasis of structural proteins required for formation and stability of the actin membrane skeleton in erythrocytes.

  20. Effects of ICG concentration on the optical properties of erythrocyte-derived nano-vectors

    Science.gov (United States)

    Tang, Jack; Bahmani, Baharak; Burns, Joshua; Nuñez, Vicente; Mac, Jenny; Bacon, Danielle; Vullev, Valentine; Sun, Victor; Jia, Wangcun; Nelson, J. S.; Anvari, Bahman

    2015-03-01

    Erythrocyte-based nanoparticle platforms can offer long circulation times not offered by traditional drug delivery methods. We have developed a novel erythrocyte-based nanoparticle doped with indocyanine green (ICG), the only FDA-approved near-infrared chromophore. Here, we report on the absorption and fluorescence emission characteristics of these nanoparticles fabricated using ICG concentrations in the range of 161-323 μM. These nanoparticles may serve as biocompatible optical materials for various clinical imaging and phototherapeutic applications.