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Sample records for mammalian hemoglobins effect

  1. Structural analysis of fish versus mammalian hemoglobins: effect of the heme pocket environment on autooxidation and hemin loss.

    PubMed

    Aranda, Roman; Cai, He; Worley, Chad E; Levin, Elena J; Li, Rong; Olson, John S; Phillips, George N; Richards, Mark P

    2009-04-01

    The underlying stereochemical mechanisms for the dramatic differences in autooxidation and hemin loss rates of fish versus mammalian hemoglobins (Hb) have been examined by determining the crystal structures of perch, trout IV, and bovine Hb at high and low pH. The fish Hbs autooxidize and release hemin approximately 50- to 100-fold more rapidly than bovine Hb. Five specific amino acid replacements in the CD corner and along the E helix appear to cause the increased susceptibility of fish Hbs to oxidative degradation compared with mammalian Hbs. Ile is present at the E11 helical position in most fish Hb chains whereas a smaller Val residue is present in all mammalian alpha and beta chains. The larger IleE11 side chain sterically hinders bound O(2) and facilitates dissociation of the neutral superoxide radical, enhancing autooxidation. Lys(E10) is found in most mammalian Hb and forms favorable electrostatic and hydrogen bonding interactions with the heme-7-propionate. In contrast, Thr(E10) is present in most fish Hbs and is too short to stabilize bound heme, and causes increased rates of hemin dissociation. Especially high rates of hemin loss in perch Hb are also due to a lack of electrostatic interaction between His(CE3) and the heme-6 propionate in alpha subunits whereas this interaction does occur in trout IV and bovine Hb. There is also a larger gap for solvent entry into the heme crevice near beta CD3 in the perch Hb (approximately 8 A) compared with trout IV Hb (approximately 6 A) which in turn is significantly higher than that in bovine Hb (approximately 4 A) at low pH. The amino acids at CD4 and E14 differ between bovine and the fish Hbs and have the potential to modulate oxidative degradation by altering the orientation of the distal histidine and the stability of the E-helix. Generally rapid rates of lipid oxidation in fish muscle can be partly attributed to the fact that fish Hbs are highly susceptible to oxidative degradation.

  2. Hemoglobin

    MedlinePlus

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Hemoglobin Share this page: Was this page helpful? Also known as: Hgb; Hb; H and H (Hemoglobin and Hematocrit) Formal name: Hemoglobin Related tests: Complete ...

  3. Bohr effect of hemoglobins: Accounting for differences in magnitude.

    PubMed

    Okonjo, Kehinde O

    2015-09-07

    The basis of the difference in the Bohr effect of various hemoglobins has remained enigmatic for decades. Fourteen amino acid residues, identical in pairs and located at specific 'Bohr group positions' in human hemoglobin, are implicated in the Bohr effect. All 14 are present in mouse, 11 in dog, eight in pigeon and 13 in guinea pig hemoglobin. The Bohr data for human and mouse hemoglobin are identical: the 14 Bohr groups appear at identical positions in both molecules. The dog data are different from the human because three Bohr group positions are occupied by non-ionizable groups in dog hemoglobin; the pigeon data are vastly different from the human because six Bohr group positions are occupied by non-ionizable groups in pigeon hemoglobin. The guinea pig data are quite complex. Quantitative analyses showed that only the pigeon data could be fitted with the Wyman equation for the Bohr effect. We demonstrate that, apart from guinea pig hemoglobin, the difference between the Bohr effect of each of the other hemoglobins and of pigeon hemoglobin can be accounted for quantitatively on the basis of the occupation of some of their Bohr group positions by non-ionizable groups in pigeon hemoglobin. We attribute the anomalous guinea pig result to a new salt-bridge formed in its R2 quaternary structure between the terminal NH3(+) group of one β-chain and the COO(-) terminal group of the partner β-chain in the same molecule. The pKas of this NH3(+) group are 6.33 in the R2 and 4.59 in the T state.

  4. Effects of thyroid status on glycated hemoglobin

    PubMed Central

    Bhattacharjee, Rana; Thukral, Anubhav; Chakraborty, Partha Pratim; Roy, Ajitesh; Goswami, Soumik; Ghosh, Sujoy; Mukhopadhyay, Pradip; Mukhopadhyay, Satinath; Chowdhury, Subhankar

    2017-01-01

    Introduction: Glycated hemoglobin (HbA1c) can be altered in different conditions. We hypothesize that HbA1c levels may change due to altered thyroid status, possibly due to changes in red blood cell (RBC) turnover. Objectives: The objective of this study was to determine the effects of altered thyroid status on HbA1c levels in individuals without diabetes, with overt hyper- and hypo-thyroidism, and if present, whether such changes in HbA1c are reversed after achieving euthyroid state. Methods: Euglycemic individuals with overt hypo- or hyper-thyroidism were selected. Age- and sex-matched controls were recruited. Baseline HbA1c and reticulocyte counts (for estimation of RBC turnover) were estimated in all the patients and compared. Thereafter, stable euthyroidism was achieved in a randomly selected subgroup and HbA1c and reticulocyte count was reassessed. HbA1c values and reticulocyte counts were compared with baseline in both the groups. Results: Hb A1c in patients initially selected was found to be significantly higher in hypothyroid group. HbA1c values in hyperthyroid patients were not significantly different from controls. HbA1c reduction and rise in reticulocyte count were significant in hypothyroid group following treatment without significant change in glucose level. Hb A1c did not change significantly following treatment in hyperthyroid group. The reticulocyte count, however, decreased significantly. Conclusion: Baseline HbA1c levels were found to be significantly higher in hypothyroid patients, which reduced significantly after achievement of euthyroidism without any change in glucose levels. Significant baseline or posttreatment change was not observed in hyperthyroid patients. Our study suggests that we should be cautious while interpreting HbA1c data in patients with hypothyroidism. PMID:28217494

  5. Role of tertiary structures on the Root effect in fish hemoglobins.

    PubMed

    Ronda, Luca; Merlino, Antonello; Bettati, Stefano; Verde, Cinzia; Balsamo, Anna; Mazzarella, Lelio; Mozzarelli, Andrea; Vergara, Alessandro

    2013-09-01

    Many fish hemoglobins exhibit a marked dependence of oxygen affinity and cooperativity on proton concentration, called Root effect. Both tertiary and quaternary effects have been evoked to explain the allosteric regulation brought about by protons in fish hemoglobins. However, no general rules have emerged so far. We carried out a complementary crystallographic and microspectroscopic characterization of ligand binding to crystals of deoxy-hemoglobin from the Antarctic fish Trematomus bernacchii (HbTb) at pH6.2 and pH8.4. At low pH ligation has negligible structural effects, correlating with low affinity and absence of cooperativity in oxygen binding. At high pH, ligation causes significant changes at the tertiary structural level, while preserving structural markers of the T state. These changes mainly consist in a marked displacement of the position of the switch region CD corner towards an R-like position. The functional data on T-state crystals validate the relevance of the crystallographic observations, revealing that, differently from mammalian Hbs, in HbTb a significant degree of cooperativity in oxygen binding is due to tertiary conformational changes, in the absence of the T-R quaternary transition. This article is part of a Special Issue entitled: Oxygen Binding and Sensing Proteins.

  6. Effect of Microgravity on Mammalian Lymphocytes

    NASA Technical Reports Server (NTRS)

    Banerjee, H.; Blackshear, M.; Mahaffey, K.; Khan, A. A.; Delucas, L.

    2004-01-01

    The effect of microgravity on mammalian system is an important and interesting topic for scientific investigation, since NASA s objective is to send manned flights to planets like Mars and eventual human colonization. The Astronauts will be exposed to microgravity environment for a long duration of time during these flights. Our objective of research is to conduct in vitro studies for the effect of microgravity on mammalian immune system and nervous system. We did our preliminary investigations by exposing mammalian lymphocytes and astrocyte cells to a microgravity simulator cell bioreactor designed by NASA and manufactured at Synthecon, Inc. (USA).Our initial results showed no significant change in cytokine expression in these cells up to a time period of 120 hours exposure. Our future experiments will involve exposure for a longer period of time.

  7. Effect of Microgravity on Mammalian Lymphocytes

    NASA Technical Reports Server (NTRS)

    Banerjee, H.; Blackshear, M.; Mahaffey, K.; Knight, C.; Khan, A. A.; Delucas, L.

    2004-01-01

    The effect of microgravity on mammalian system is an important and interesting topic for scientific investigation, since NASA s objective is to send manned flights to planets like Mars and eventual human colonization.The Astronauts will be exposed to microgravity environment for a long duration of time during these flights.Our objective of research is to conduct in vitro studies for the effect of microgravity on mammalian immune system.We did our preliminary investigations by exposing mammalian lymphocytes to a microgravity simulator cell bioreactor designed by NASA and manufactured at Synthecon Inc (USA).Our initial results showed no significant change in cytokine expression in these cells for a time period of forty eight hours exposure.Our future experiments will involve exposure for a longer period of time.

  8. Effects of porcine hemoglobin on serum lipid content and fecal lipid excretion in rats.

    PubMed

    Hosomi, Ryota; Fukunaga, Kenji; Nishiyama, Toshimasa; Yoshida, Munehiro

    2014-03-01

    The purpose of this study was to elucidate the effects of dietary hemoglobin on serum and liver lipid contents in rats, and the ability of hemoglobin hydrolysates to disrupt lipid absorption. After rats had been fed on casein- or porcine hemoglobin-containing diets for 4 weeks, their serum and liver lipid contents and fecal cholesterol, bile acid, and nitrogen excretion were measured. To elucidate the mechanism of lipid absorption by dietary hemoglobin, we also examined lipase activity, micellar solubility of cholesterol, and bile acid binding activity in the presence of hemoglobin hydrolysates. Dietary hemoglobin decreased serum and liver triglyceride and cholesterol contents and increased fecal fatty acid, cholesterol, and bile acid excretion. In addition, hemoglobin hydrolysates inhibited lipase activity compared with casein hydrolysates in an in vitro study. These results suggested that the hypolipidemic effect of hemoglobin is mediated by increased fecal lipid excretion, and that decreased lipase activity by hemoglobin is at least partially responsible for this result. The observed effects were documented with an 8 g/kg hemoglobin diet, which is lower than in other studies; therefore. hemoglobin may be useful in the prevention of lifestyle-related diseases.

  9. The effect of cationic starch on hemoglobin, and the primary attempt to encapsulate hemoglobin.

    PubMed

    Gao, Wei; Sha, Baoyong; Liu, Yongchun; Wu, Daocheng; Shen, Xin; Jing, Guixia

    2015-06-01

    Though starch has been a common material used for drug delivery, it has not been used as an encapsulation material for hemoglobin-based oxygen carriers. In this study, cationic amylose (CA) was synthesized by an etherification reaction. The interaction behaviors between CA and hemoglobin (Hb) were measured by zeta potential, size, and UV-Vis absorption spectra at different pH values. Cationic starch encapsulated Hb by electrostatic adhesion, reverse micelles, and cross-linking, and showed a core shell structure with a size of around 100 nm, when measured immediately after dispersing in PBS solution. However, we found that it was prone to swell, aggregate, and leak Hb with a longer duration of dispersal in PBS.

  10. Photodynamic effect occurance in photosensitizer mixtures with albumin or blood serum, or hemoglobin and blood

    NASA Astrophysics Data System (ADS)

    Torshina, Nadezgda L.; Posypanova, Anna M.; Volkova, Anna I.

    1996-05-01

    Under laser irradiation of different photosensitizers (PS) mixtures with pure albumin or without hemolysis blood serum the photodynamic effect (PE) is scarcely to be manifested. The coupling of PS with albumins prevents the interactions of dissolved oxygen molecules with PS molecules and formation of active oxygen forms. In order to promote the PE it is necessary to add the solution of hemoglobin. The PE is readily recognized in mixtures of PS with the blood. Such mixing leads to the erythrocytes' destruction and yields uncombined hemoglobin in blood plasma. The irradiation of hemoglobin mixtures with PS leads to the destruction of hemoglobin. In this case the direct combination of oxygen molecules with hemoglobin is important for PE performance (the deoxy hemoglobin can not promote PE otherwise).

  11. Effects of Hemoglobin Variants on Hemoglobin A1c Values Measured Using a High-Performance Liquid Chromatography Method

    PubMed Central

    De-La-Iglesia, Silvia; Ropero, Paloma; Nogueira-Salgueiro, Patricia; Santana-Benitez, Jesus

    2014-01-01

    Hemoglobin A1c (HbA1c) is routinely used to monitor long-term glycemic control and for diagnosing diabetes mellitus. However, hemoglobin (Hb) gene variants/modifications can affect the accuracy of some methods. The potential effect of Hb variants on HbA1c measurements was investigated using a high-performance liquid chromatography (HPLC) method compared with an immunoturbimetric assay. Fasting plasma glucose (FPG) and HbA1c levels were measured in 42 371 blood samples. Samples producing abnormal chromatograms were further analyzed to characterize any Hb variants. Fructosamine levels were determined in place of HbA1c levels when unstable Hb variants were identified. Abnormal HPLC chromatograms were obtained for 160 of 42 371 samples. In 26 samples HbS was identified and HbA1c results correlated with FPG. In the remaining 134 samples HbD, Hb Louisville, Hb Las Palmas, Hb N-Baltimore, or Hb Porto Alegre were identified and HbA1c did not correlate with FPG. These samples were retested using an immunoturbidimetric assay and the majority of results were accurate; only 3 (with the unstable Hb Louisville trait) gave aberrant HbA1c results. Hb variants can affect determination of HbA1c levels with some methods. Laboratories should be aware of Hb variants occurring locally and choose an appropriate HbA1c testing method. PMID:25355712

  12. Hemoglobin derivatives

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003371.htm Hemoglobin derivatives To use the sharing features on this page, please enable JavaScript. Hemoglobin derivatives are altered forms of hemoglobin . Hemoglobin is ...

  13. Hemoglobin Solution Effects on the Heart: Review of 19 Research Reports.

    DTIC Science & Technology

    1986-04-01

    York: Alan R Liss, Inc.] 213-222. niEor 6. Biro GP, Heresford-Kroeger D. 1180. The effect of hemodilut ion with st roma-free hemoglobin and dextran on...1980. The effect of hemodilution with stroma-free hemoglobin and dextran on collateral perfusion of ischemic myocardium in the dog. Am Heart J 99:64-75...Nine dogs received stroma-free hemoglobin solution (Group 1), 9 dogs received their shed blood (Group 2) and 6 dogs received a 6% solution of Dextran -70

  14. Anti- and pro-oxidant effects of (+)-catechin on hemoglobin-induced protein oxidative damage.

    PubMed

    Lu, Naihao; Chen, Puqing; Yang, Qin; Peng, Yi-Yuan

    2011-06-01

    Evidence to support the role of heme proteins as major inducers of oxidative damage is increasingly present. Flavonoids have been widely used to ameliorate oxidative damage in vivo and in vitro, where the mechanism of this therapeutic action was usually dependent on their anti-oxidant effects. In this study, we investigated the influence of (+)-catechin, a polyphenol identified in tea, cocoa, and red wine, on hemoglobin-induced protein oxidative damage. It was found that (+)-catechin had the capacities to act as a free radical scavenger and reducing agent to remove cytotoxic ferryl hemoglobin, demonstrating apparent anti-oxidant activities. However, the presence of (+)-catechin surprisingly promoted hemoglobin-induced protein oxidation, which was probably due to the ability of this anti-oxidant to rapidly trigger the oxidative degradation of normal hemoglobin. In addition, hemoglobin-H2O2-induced protein carbonyl formation was significantly enhanced by (+)-catechin at lower concentrations, while it was efficiently inhibited when higher concentrations were used. These novel results showed that the dietary intake and therapeutic use of catechins might possess pro-oxidant activity through aggravating hemoglobin-related oxidative damage. The dual effects on hemoglobin redox reactions may provide new insights into the physiological implications of tea extract and wine (catechins) with cellular heme proteins.

  15. Mechanisms of the adjuvant effect of hemoglobin in experimental peritonitis. VII. Hemoglobin does not inhibit clearance of Escherichia coli from the peritoneal cavity

    SciTech Connect

    Dunn, D.L.; Barke, R.A.; Lee, J.T. Jr.; Condie, R.M.; Humphrey, E.W.; Simmons, R.L.

    1983-09-01

    Hemoglobin has been shown to be a potent adjuvant in experimental Escherichia coli peritonitis, although a satisfactory mechanistic rationale is still obscure. Hemoglobin has been thought to impair intraperitoneal neutrophil function, delay clearance of bacteria from the peritoneal cavity by the normal absorptive mechanisms, or directly enhance bacterial growth. Using highly purified stroma-free hemoglobin (SFHgb), we have largely discounted any direct effect of hemoglobin on peritoneal white blood cell function. In the present study, we confirmed that uncontrolled proliferation of bacteria takes place in the presence of hemoglobin in the peritoneal cavity. Nonviable 5-iododeoxyuridine /sup 125/I-labelled bacteria were then used to directly study peritoneal clearance kinetics, eliminating the problem of bacterial growth. SFHgb had no influence on the removal of intraperitoneal bacteria. The rate of bloodstream appearance of radiolabel was similar with or without intraperitoneal SFHgb. Thus, SFHgb does not prevent clearance of bacteria from the peritoneal cavity by interfering with normal host clearance mechanisms. SFHgb may act as a bacterial growth adjuvant, either by serving as a bacterial nutrient or by suitably modifying the environment so that extensive bacterial proliferation can occur. The latter hypothesis appears to be an area in which investigation concerning the adjuvant effect of hemoglobin may prove most fruitful.

  16. Effects of Hemoglobin-Based Oxygen Carriers on Blood Coagulation

    PubMed Central

    Roghani, Kimia; Holtby, Randall J.; Jahr, Jonathan S.

    2014-01-01

    For many decades, Hemoglobin-based oxygen carriers (HBOCs) have been central in the development of resuscitation agents that might provide oxygen delivery in addition to simple volume expansion. Since 80% of the world population lives in areas where fresh blood products are not available, the application of these new solutions may prove to be highly beneficial (Kim and Greenburg 2006). Many improvements have been made to earlier generation HBOCs, but various concerns still remain, including coagulopathy, nitric oxide scavenging, platelet interference and decreased calcium concentration secondary to volume expansion (Jahr et al. 2013). This review will summarize the current challenges faced in developing HBOCs that may be used clinically, in order to guide future research efforts in the field. PMID:25514567

  17. Role of β/δ101Gln in regulating the effect of temperature and allosteric effectors on oxygen affinity in woolly mammoth hemoglobin.

    PubMed

    Yuan, Yue; Byrd, Catherine; Shen, Tong-Jian; Simplaceanu, Virgil; Tam, Tsuey Chyi S; Ho, Chien

    2013-12-10

    The oxygen affinity of woolly mammoth hemoglobin (rHb WM) is less affected by temperature change than that of Asian elephant hemoglobin (rHb AE) or human normal adult hemoglobin (Hb A). We report here a biochemical-biophysical study of Hb A, rHb AE, rHb WM, and three rHb WM mutants with amino acid substitutions at β/δ101 (β/δ101Gln→Glu, Lys, or Asp) plus a double and a triple mutant, designed to clarify the role of the β/δ101 residue. The β/δ101Gln residue is important for responding to allosteric effectors, such as phosphate, inositol hexaphosphate (IHP), and chloride. The rHb WM mutants studied generally have higher affinity for oxygen under various conditions of pH, temperature, and salt concentration, and in the presence or absence of organic phosphate, than do rHb WM, rHb AE, and Hb A. Titrations for the O2 affinity of these mutant rHbs as a function of chloride concentration indicate a lower heterotopic effect of this anion due to the replacement of β/δ101Gln in rHb WM. The alkaline Bohr effect of rHb WM and its mutants is reduced by 20-50% compared to that of Hb A and is independent of changes in temperature, in contrast to what has been observed in the hemoglobins of most mammalian species, including human. The results of our study on the temperature dependence of the O2 affinity of rHb WM and its mutant rHbs illustrate the important role of β/δ101Gln in regulating the functional properties of these hemoglobins.

  18. The effect of gamma-rays on the hemoglobin of whole-body irradiated mice

    NASA Astrophysics Data System (ADS)

    Ashry, H. A.; Selim, N. S.; El-Behay, A. Z.

    1994-07-01

    Changes in the UV-visible absorption spectrum of mouse hemoglobin as a result of whole body irradiation were studied. White albino adult mice were exposed to a Cs-137 γ-source at a dose rate of 47.5 Gy/h to different absorbed dose values ranging from 1 to 8 Gy. Blood specimens were taken 24 h after irradiation. The UV-visible absorption spectra of hemoglobin of irradiated and control mice were measured in the wavelength range from 200 to 700 nm. The obtained results showed significant changes in the bands measured at 340 nm, in the Soret band measured at 410 nm, also, the α- and β-bands measured at 537 and 572 nm showed significant decrease in intensity with the absorbed dose increase. The absorbance measured at 630 nm showed no significant changes. The radiation effect on the animal hemoglobin was discussed on the basis of the obtained results.

  19. Effect of methylprednisolone on mammalian neuronal networks in vitro.

    PubMed

    Wittstock, Matthias; Rommer, Paulus S; Schiffmann, Florian; Jügelt, Konstantin; Stüwe, Simone; Benecke, Reiner; Schiffmann, Dietmar; Zettl, Uwe K

    2015-01-01

    Glucocorticosteroids (GCS) are widely used for the treatment of neurological diseases, e.g. multiple sclerosis. High levels of GCS are toxic to the central nervous system and can produce adverse effects. The effect of methylprednisolone (MP) on mammalian neuronal networks was studied in vitro. We demonstrate a dose-dependent excitatory effect of MP on cultured neuronal networks, followed by a shut-down of electrical activity using the microelectrode array technique.

  20. Effects of habitat light intensity on mammalian eye shape.

    PubMed

    Veilleux, Carrie C; Lewis, Rebecca J

    2011-05-01

    Many aspects of mammalian visual anatomy vary with activity pattern, reflecting the divergent selective pressures imposed by low light and high light visual environments. However, ambient light intensity can also differ substantially between and within habitats due to differences in foliage density. We explored the effects of interhabitat and intrahabitat variation in light intensity on mammalian visual anatomy. Data on relative cornea size, activity pattern, and habitat type were collected from the literature for 209 terrestrial mammal species. In general, mammalian relative cornea size significantly varied by habitat type. In within-order and across-mammal analyses, diurnal and cathemeral mammals from forested habitats exhibited relatively larger corneas than species from more open habitats, reflecting an adaptation to increase visual sensitivity in forest species. However, in all analyses, we found no habitat-type effect in nocturnal species, suggesting that nocturnal mammals may experience selection to maximize visual sensitivity across all habitats. We also examined whether vertical strata usage affected relative cornea size in anthropoid primates. In most analyses, species occupying lower levels of forests and woodlands did not exhibit relatively larger corneas than species utilizing higher levels. Thus, unlike differences in intensity between habitat types, differences in light intensity between vertical forest strata do not appear to exert a strong selective pressure on visual morphology. These results suggest that terrestrial mammal visual systems reflect specializations for habitat variation in light intensity, and that habitat type as well as activity pattern have influenced mammalian visual evolution.

  1. Effects of heat stress on mammalian reproduction

    PubMed Central

    Hansen, Peter J.

    2009-01-01

    Heat stress can have large effects on most aspects of reproductive function in mammals. These include disruptions in spermatogenesis and oocyte development, oocyte maturation, early embryonic development, foetal and placental growth and lactation. These deleterious effects of heat stress are the result of either the hyperthermia associated with heat stress or the physiological adjustments made by the heat-stressed animal to regulate body temperature. Many effects of elevated temperature on gametes and the early embryo involve increased production of reactive oxygen species. Genetic adaptation to heat stress is possible both with respect to regulation of body temperature and cellular resistance to elevated temperature. PMID:19833646

  2. Nonantibiotic Effects of Fluoroquinolones in Mammalian Cells.

    PubMed

    Badal, Sujan; Her, Yeng F; Maher, L James

    2015-09-04

    Fluoroquinolones (FQ) are powerful broad-spectrum antibiotics whose side effects include renal damage and, strangely, tendinopathies. The pathological mechanisms underlying these toxicities are poorly understood. Here, we show that the FQ drugs norfloxacin, ciprofloxacin, and enrofloxacin are powerful iron chelators comparable with deferoxamine, a clinically useful iron-chelating agent. We show that iron chelation by FQ leads to epigenetic effects through inhibition of α-ketoglutarate-dependent dioxygenases that require iron as a co-factor. Three dioxygenases were examined in HEK293 cells treated with FQ. At sub-millimolar concentrations, these antibiotics inhibited jumonji domain histone demethylases, TET DNA demethylases, and collagen prolyl 4-hydroxylases, leading to accumulation of methylated histones and DNA and inhibition of proline hydroxylation in collagen, respectively. These effects may explain FQ-induced nephrotoxicity and tendinopathy. By the same reasoning, dioxygenase inhibition by FQ was predicted to stabilize transcription factor HIF-1α by inhibition of the oxygen-dependent hypoxia-inducible transcription factor prolyl hydroxylation. In dramatic contrast to this prediction, HIF-1α protein was eliminated by FQ treatment. We explored possible mechanisms for this unexpected effect and show that FQ inhibit HIF-1α mRNA translation. Thus, FQ antibiotics induce global epigenetic changes, inhibit collagen maturation, and block HIF-1α accumulation. We suggest that these mechanisms explain the classic renal toxicities and peculiar tendinopathies associated with FQ antibiotics.

  3. Nonantibiotic Effects of Fluoroquinolones in Mammalian Cells*

    PubMed Central

    Badal, Sujan; Her, Yeng F.; Maher, L. James

    2015-01-01

    Fluoroquinolones (FQ) are powerful broad-spectrum antibiotics whose side effects include renal damage and, strangely, tendinopathies. The pathological mechanisms underlying these toxicities are poorly understood. Here, we show that the FQ drugs norfloxacin, ciprofloxacin, and enrofloxacin are powerful iron chelators comparable with deferoxamine, a clinically useful iron-chelating agent. We show that iron chelation by FQ leads to epigenetic effects through inhibition of α-ketoglutarate-dependent dioxygenases that require iron as a co-factor. Three dioxygenases were examined in HEK293 cells treated with FQ. At sub-millimolar concentrations, these antibiotics inhibited jumonji domain histone demethylases, TET DNA demethylases, and collagen prolyl 4-hydroxylases, leading to accumulation of methylated histones and DNA and inhibition of proline hydroxylation in collagen, respectively. These effects may explain FQ-induced nephrotoxicity and tendinopathy. By the same reasoning, dioxygenase inhibition by FQ was predicted to stabilize transcription factor HIF-1α by inhibition of the oxygen-dependent hypoxia-inducible transcription factor prolyl hydroxylation. In dramatic contrast to this prediction, HIF-1α protein was eliminated by FQ treatment. We explored possible mechanisms for this unexpected effect and show that FQ inhibit HIF-1α mRNA translation. Thus, FQ antibiotics induce global epigenetic changes, inhibit collagen maturation, and block HIF-1α accumulation. We suggest that these mechanisms explain the classic renal toxicities and peculiar tendinopathies associated with FQ antibiotics. PMID:26205818

  4. Effect of Carbon Nanotubes on Mammalian Cells

    NASA Astrophysics Data System (ADS)

    Chen, Michelle; Ahmed, Asma; Black, Melanie; Kawamoto, Nicole; Lucas, Jessica; Pagala, Armie; Pham, Tram; Stankiewicz, Sara; Chen, Howard

    2010-03-01

    Carbon Nanotubes possess extraordinary electrical, mechanical, and thermal properties. Research on applying the carbon nanotubes for ultrasensitive detection, disease diagnosis, and drug delivery is rapidly developing. While the fundamental and technological findings on carbon nanotubes show great promise, it is extremely important to investigate the effect of the carbon nanotubes on human health. In our experiments, we introduce purified carbon nanotubes in suspension to ovary cells cultured from Hamsters. These cells are chosen since they show robust morphological changes associated with cytotoxicity that can easily be observed under a light microscope. We will discuss the toxicity of carbon nanotubes by characterizing the cell morphology and viability as a function of time and the concentration of carbon nanotube suspension.

  5. Space radiation effects on plant and mammalian cells

    NASA Astrophysics Data System (ADS)

    Arena, C.; De Micco, V.; Macaeva, E.; Quintens, R.

    2014-11-01

    The study of the effects of ionizing radiation on organisms is related to different research aims. The current review emphasizes the studies on the effects of different doses of sparsely and densely ionizing radiation on living organisms, with the final purpose of highlighting specific and common effects of space radiation in mammals and plants. This topic is extremely relevant in the context of radiation protection from space environment. The response of different organisms to ionizing radiation depends on the radiation quality/dose and/or the intrinsic characteristics of the living system. Macromolecules, in particular DNA, are the critical targets of radiation, even if there is a strong difference between damages encountered by plant and mammalian cells. The differences in structure and metabolism between the two cell types are responsible for the higher resistance of the plant cell compared with its animal counterpart. In this review, we report some recent findings from studies performed in Space or on Earth, simulating space-like levels of radiation with ground-based facilities, to understand the effect of ionizing radiation on mammalian and plant cells. In particular, our attention is focused on genetic alterations and repair mechanisms in mammalian cells and on structures and mechanisms conferring radioresistance to plant cells.

  6. Hemoglobin (image)

    MedlinePlus

    Hemoglobin is the most important component of red blood cells. It is composed of a protein called ... exchanged for carbon dioxide. Abnormalities of an individual's hemoglobin value can indicate defects in the normal balance ...

  7. Effects of lead and cadmium co-exposure on hemoglobin in a Chinese population.

    PubMed

    Chen, Xiao; Zhou, Hao; Li, Xiaoshuang; Wang, Zhongqiu; Zhu, Guoying; Jin, Taiyi

    2015-03-01

    Cadmium (Cd) and lead (Pb) show adverse effects on hemoglobin. But most studies are focussed on one single agent. In this study, we observed the main and interactive effects of Cd and Pb on the hemoglobin level in a Chinese population. A total of 308 persons (202 women and 106 men), living in controlled and polluted areas, were included in this study. Blood and urine were collected to determine the levels of hemoglobin (Hb), Cd, Pb, and urinary N-acetyl-β-D-glucosaminidase (UNAG). The Cd and Pb level of subjects living in the polluted area were significantly higher compared to those living in the control area (p<0.05). The level of hemoglobin was declined with the increasing BPb (p<0.05) and BCd in women. The Hb of women and men with the highest level of BCd and BPb were decreased by 8.3g/L and 10.7 g/L compared to those with the lowest level of BCd and BPb, respectively. The Hb level of those women and men with the highest level of UNAG decreased by 4.2g/L and 17.2g/L compared with those with low level of UNAG, respectively. Hb was negatively associated with BPb, BCd, and UNAG. This study evidenced that Cd and Pb can influence Hb level. In addition, our study shows that Cd and Pb may have interactive effects on Hb and Hb level was correlated with tubular dysfunction caused by Cd and Pb exposure.

  8. Blood lead: Its effect on trace element levels and iron structure in hemoglobin

    NASA Astrophysics Data System (ADS)

    Jin, C.; Li, Y.; Li, Y. L.; Zou, Y.; Zhang, G. L.; Normura, M.; Zhu, G. Y.

    2008-08-01

    Lead is a ubiquitous environmental pollutant that induce a broad range of physiological and biochemical dysfunctions. The purpose of this study was to investigate its effects on trace elements and the iron structure in hemoglobin. Blood samples were collected from rats that had been exposed to lead. The concentration of trace elements in whole blood and blood plasma was determined by ICP-MS and the results indicate that lead exists mainly in the red blood cells and only about 1-3% in the blood plasma. Following lead exposure, the concentrations of zinc and iron in blood decrease, as does the hemoglobin level. This indicates that the heme biosynthetic pathway is inhibited by lead toxicity and that lead poisoning-associated anemia occurs. The selenium concentration also decreases after lead exposure, which may lead to an increased rate of free radical production. The effect of lead in the blood on iron structure in hemoglobin was determined by EXAFS. After lead exposure, the Fe-O bond length increases by about 0.07 Å and the Fe-Np bond length slightly increases, but the Fe-N ɛ bond length remains unchanged. This indicates that the blood content of Hb increases, but that the content of HbO 2 decreases.

  9. Hemoglobin Effects on Nitric Oxide Mediated Hypoxic Vasodilation.

    PubMed

    Rong, Zimei; Cooper, Chris E

    2016-01-01

    The brain responds to hypoxia with an increase in cerebral blood flow (CBF). However, such an increase is generally believed to start only after the oxygen tension decreases to a certain threshold level. Although many mechanisms (different vasodilator and different generation and metabolism mechanisms of the vasodilator) have been proposed at the molecular level, none of them has gained universal acceptance. Nitric oxide (NO) has been proposed to play a central role in the regulation of oxygen supply since it is a vasodilator whose production and metabolism are both oxygen dependent. We have used a computational model that simulates blood flow and oxygen metabolism in the brain (BRAINSIGNALS) to test mechanism by which NO may elucidate hypoxic vasodilation. The first model proposed that NO was produced by the enzyme nitric oxide synthase (NOS) and metabolized by the mitochondrial enzyme cytochrome c oxidase (CCO). NO production declined with decreasing oxygen concentration given that oxygen is a substrate for nitric oxide synthase (NOS). However, this was balanced by NO metabolism by CCO, which also declined with decreasing oxygen concentration. However, the NOS effect was dominant; the resulting model profiles of hypoxic vasodilation only approximated the experimental curves when an unfeasibly low K m for oxygen for NOS was input into the model. We therefore modified the model such that NO generation was via the nitrite reductase activity of deoxyhemoglobin instead of NOS, whilst keeping the metabolism of NO by CCO the same. NO production increased with decreasing oxygen concentration, leading to an improved reproduction of the experimental CBF versus PaO2 curve. However, the threshold phenomenon was not perfectly reproduced. In this present work, we incorporated a wider variety of oxygen dependent and independent NO production and removal mechanisms. We found that the addition of NO removal via oxidation to nitrate mediated by oxyhemoglobin resulted in the

  10. [Effects of radiofrequency electromagnetic fields on mammalian spermatogenesis].

    PubMed

    Susa, Martina; Pavicić, Ivan

    2007-12-01

    This article reviews studies about the effects of radiofrequency electromagnetic (RF EM) fields on male reproductive system and reproductive health in mammals. According to current data, there are almost 4 million active mobile phone lines in Croatia while this number has risen to 2 billion in the world. Increased use of mobile technology raises scientific and public concern about possible hazardous effects of RF fields on human health. The effects of radiofrequencies on reproductive health and consequences for the offspring are still mainly unknown. A number of in vivo and in vitro studies indicated that RF fields could interact with charged intracellular macromolecular structures. Results of several laboratory studies on animal models showed how the RF fields could affect the mammalian reproductive system and sperm cells. Inasmuch as, in normal physiological conditions spermatogenesis is a balanced process of division, maturation and storage of cells, it is particularly vulnerable to the chemical and physical environmental stimuli. Especially sensitive could be the cytoskeleton, composed of charged proteins; actin, intermedial filaments and microtubules. Cytoskeleton is a functional and structural part of the cell that has important role in the sperm motility, and is actively involved in the morphologic changes that occur during mammalian spermiogenesis.

  11. Toxic effects of Karenia mikimotoi extracts on mammalian cells

    NASA Astrophysics Data System (ADS)

    Chen, Yang; Yan, Tian; Yu, Rencheng; Zhou, Mingjiang

    2011-07-01

    Karenia is one of the most harmful and representative red tide genus in a temperate zone. Blooms caused by this genus have resulted in massive fish death in the South China Sea and the East China Sea. However, the potential effects of this dinoflagellate on human health through the transfer of toxins via marine food webs, and the mechanisms of toxicity, are still unknown. Therefore, we examined the toxic effects of a strain of K. mikimotoi (isolated from the South China Sea) on the proliferation and morphology of four mammalian cell lines (two normal cell lines and two cancer cell lines). In addition, we carried out a preliminary investigation on the mechanism of toxicity of the alga. The results show that the polar lipid-soluble component of K. mikimotoi significantly inhibited proliferation of the four cell lines, and resulted in the cells becoming spherical, swollen and damaged. The result of Annexin V and PI double-staining confirmed that cell membranes were disrupted. The malonaldehyde (MDA) contents in the medium of the four cell lines treated with the polar-lipid extracts all increased significantly, which indicates that the polar-lipid toxins produced by K. mikimotoi could adversely affect mammalian cells by inducing lipid peroxidation. We conclude that K. mikimotoi is a potential threat to human health, and the comprehensive effect of this dinoflagellate and its mechanisms should be investigated further.

  12. Effects of naphthalene on the hemoglobin concentration and oxygen uptake of daphnia magna

    SciTech Connect

    Crider, J.Y.; Wilhm, J.; Harman, H.J.

    1982-01-01

    In addition to acute testing for survival of Daphnia magna exposed to naphthalene, various physiological tests were made. Short term studies were conducted to calculate LC50 values and physiological responses. Daphnia of 24 h were fed initially 0.25 ml food/l and the pH, dissolved oxygen and temperature, conductivity, swimming movements, and the number of survivors were determined at 0, 24, and 48 h. These experiments were run at least three times and the dosage-mortality curves were determined by the use of probit and regression analyses. Physiological studies were made for concentrations of 1, 5, and 10 mg/l. Oxygen consumption of Daphnia was measured polarographically and a carboxyhemoglobin method was used to measure total hemoglobin. The hemoglobin concentrations of the treated organisms decreased from 102 nmoles/animal at 1 mg/l naphthalene to 67 nmoles/animal at 9 mg/l. Oxygen uptake decreased from 37 nmoles/animal/h at 1 mg/l to 28 nmoles/animal/h at8 mg/l. Results show that hemoglobin concentration and oxygen uptake may be useful tools in assessing water quality and its effects on the biota. (JMT)

  13. Effects of laser acupoint irradiation on blood glucose and glycosylated hemoglobin in type 2 diabetes mellitus

    NASA Astrophysics Data System (ADS)

    Hui-Hui, Liu; Guo-Xin, Xiong; Li-Ping, Zhang

    2016-06-01

    To investigate the effects of semiconductor laser acupoint irradiation on blood glucose, glycosylated hemoglobin and physical fitness in type 2 diabetes mellitus, 44 cases of type 2 diabetic patients were randomly divided into a control group and a treatment group. All patients in both groups were given a drug treatment. The Hegu, Quchi and Zusanli acupoints of patients in the treatment group were then irradiated daily for 15 d with a 10 MW semiconductor laser. Before and after treatment, patients in both groups underwent a variety of tests and measurements: a two-hour postprandial blood glucose test; a glycosylated hemoglobin test and body mass index (BMI), waist-to-hip ratio (WHR) and body fat percentage (BFP) measurements. The data detected after treatment greatly decreased in the treatment group and was significantly different from that in the control group. It is shown that the acupoint irradiation with a semiconductor laser can improve two-hour postprandial blood glucose, glycosylated hemoglobin and some physical fitness measurements in type 2 diabetes mellitus patients.

  14. The optimal target hemoglobin.

    PubMed

    Ritz, E; Schwenger, V

    2000-07-01

    There is still controversy concerning the optimal target hemoglobin during treatment with recombinant human erythropoietin (rHuEPO). Some evidence suggests that hemoglobin concentrations higher than currently recommended lead to improvements in cognitive function, physical performance, and rehabilitation. At least in patients with advanced cardiac disease, however, one controlled trial failed to show a benefit from normalizing predialysis hemoglobin concentrations. In contrast, preliminary observations in three additional studies (albeit with limited statistical power) failed to show adverse cardiovascular effects from normalization of hemoglobin, but definite benefit with respect to quality of life, physical performance, and cardiac geometry. These observations are consistent with the notion that hemoglobin concentrations higher than those recommended by the National Kidney Foundation Dialysis Outcomes Quality Initiative Anemia Work Group are beneficial, at least in patients without advanced cardiac disease.

  15. Quinones: reactions with hemoglobin, effects within erythrocytes and potential for antimalarial development

    SciTech Connect

    Denny, B.J.

    1986-01-01

    The focus of this research was to characterize the interactions of some simple quinone like compounds with purified hemoglobin and to study the effects of these compounds within erythrocytes. It is proposed that these sorts of agents can have an antimalarial effect. The simplest compounds chosen for study were benzoquinone, methylquinone (toluquinone) and hydroquinone. When /sup 14/C-quinone was reacted with purified hemoglobin (Hb) there was rapid binding of the first two moles of substrate per Hb molecule. An unusual property of the modified Hb's is that in the presence of a redox sensitive agent such as cytochrome c they are capable of generating superoxide anions. Within erythrocytes, quinone and toluquinone which differ only by a single methyl group have completely different effects. Toluquinone causes the cells to hemolyse and the effect was enhanced when the erythrocyte superoxide dismutase was inhibited; the effect was diminished when scavengers of activated oxygen such as histidine, mannitol and vital E were present. Benzoquinone on the other hand did not cause the cells to hemolyse and instead appeared to protect the cells from certain hemolytic stresses. Growth of malaria parasites in erythrocytes has been shown to be inhibited by activated forms of oxygen, also some quinone like agents in the past have been shown to inhibit the parasite's metabolism. An initial experiment with erythrocytes infected with malaria parasites showed that quinone and toluquinone could both inhibit the growth rate of parasites.

  16. Mutual effects of proton and sodium chloride on oxygenation of liganded human hemoglobin.

    PubMed

    Lepeshkevich, Sergei V; Dzhagarov, Boris M

    2005-12-01

    The different effects of pH and NaCl on individual O2-binding properties of alpha and beta subunits within liganded tetramer and dimer of human hemoglobin (HbA) were examined in a number of laser time-resolved spectroscopic measurements. A previously proposed approach [Dzhagarov BM & Lepeshkevich SV (2004) Chem Phys Lett390, 59-64] was used to determine the extent of subunit dissociation rate constant difference and subunit affinity difference from a single flash photolysis experiment. To investigate the effect of NaCl concentration on the association and dissociation rate constants we carried out a series of experiments at four different concentrations (0.1, 0.5, 1.0 and 2.0 m NaCl) over the pH range of the alkaline Bohr effect. As the data suggest, the individual properties of the alpha and beta subunits within the completely liganded tetrameric hemoglobin did not depend on pH under salt-free conditions. However, different effects NaCl on the individual kinetic properties of the alpha and beta subunits were revealed. Regulation of the O2-binding properties of the alpha and beta subunits within the liganded tetramer is proposed to be attained in two quite different ways.

  17. The calming effect of maternal carrying in different mammalian species.

    PubMed

    Esposito, Gianluca; Setoh, Peipei; Yoshida, Sachine; Kuroda, Kumi O

    2015-01-01

    Attachment theory postulates that mothers and their infants possess some basic physiological mechanisms that favor their dyadic interaction and bonding. Many studies have focused on the maternal physiological mechanisms that promote attachment (e.g., mothers' automatic responses to infant faces and/or cries), and relatively less have examined infant physiology. Thus, the physiological mechanisms regulating infant bonding behaviors remain largely undefined. This review elucidates some of the neurobiological mechanisms governing social bonding and cooperation in humans by focusing on maternal carrying and its beneficial effect on mother-infant interaction in mammalian species (e.g., in humans, big cats, and rodents). These studies show that infants have a specific calming response to maternal carrying. A human infant carried by his/her walking mother exhibits a rapid heart rate decrease, and immediately stops voluntary movement and crying compared to when he/she is held in a sitting position. Furthermore, strikingly similar responses were identified in mouse rodents, who exhibit immobility, diminished ultra-sonic vocalizations and heart rate. In general, the studies described in the current review demonstrate the calming effect of maternal carrying to be comprised of a complex set of behavioral and physiological components, each of which has a specific postnatal time window and is orchestrated in a well-matched manner with the maturation of the infants. Such reactions could have been evolutionarily adaptive in mammalian mother-infant interactions. The findings have implications for parenting practices in developmentally normal populations. In addition, we propose that infants' physiological response may be useful in clinical assessments as we discuss possible implications on early screening for child psychopathology (e.g., autism spectrum disorders and perinatal brain disorders).

  18. An Order-Disorder Transition Plays a Role in Switching Off the Root Effect in Fish Hemoglobins*

    PubMed Central

    Vergara, Alessandro; Vitagliano, Luigi; Merlino, Antonello; Sica, Filomena; Marino, Katia; Verde, Cinzia; di Prisco, Guido; Mazzarella, Lelio

    2010-01-01

    The Root effect is a widespread property among fish hemoglobins whose structural basis remains largely obscure. Here we report a crystallographic and spectroscopic characterization of the non-Root-effect hemoglobin isolated from the Antarctic fish Trematomus newnesi in the deoxygenated form. The crystal structure unveils that the T state of this hemoglobin is stabilized by a strong H-bond between the side chains of Asp95α and Asp101β at the α1β2 and α2β1 interfaces. This unexpected finding undermines the accepted paradigm that correlates the presence of this unusual H-bond with the occurrence of the Root effect. Surprisingly, the T state is characterized by an atypical flexibility of two α chains within the tetramer. Indeed, regions such as the CDα corner and the EFα pocket, which are normally well ordered in the T state of tetrameric hemoglobins, display high B-factors and non-continuous electron densities. This flexibility also leads to unusual distances between the heme iron and the proximal and distal His residues. These observations are in line with Raman micro-spectroscopy studies carried out both in solution and in the crystal state. The findings here presented suggest that in fish hemoglobins the Root effect may be switched off through a significant destabilization of the T state regardless of the presence of the inter-aspartic H-bond. Similar mechanisms may also operate for other non-Root effect hemoglobins. The implications of the flexibility of the CDα corner for the mechanism of the T-R transition in tetrameric hemoglobins are also discussed. PMID:20610398

  19. Effects of polymerization on the oxygen carrying and redox properties of diaspirin cross-linked hemoglobin.

    PubMed

    Rogers, M S; Ryan, B B; Cashon, R E; Alayash, A I

    1995-04-27

    Human hemoglobin site specifically cross-linked with bis(3,5-dibromosalicyl)fumarate results in a low oxygen affinity hemoglobin-based red cell substitute (alpha-DBBF). Polymerization of alpha-DBBF by bis(maleoylglycylamide) polyethylene glycol (BMAA-PEG) yields poly alpha-DBBF which offers the added benefits of reduced renal clearance and increased retention in the vascular circulation. Oxygen equilibrium curves for poly alpha-DBBF are slightly left-shifted (higher O2 affinity) compared to those of alpha-DBBF; with a diminished cooperativity and a reduced Bohr effect. In rapid mixing experiments (oxygen dissociation and carbon monoxide binding), poly alpha-DBBF exhibits a several fold increase in the overall rate of deoxygenation and carbon monoxide binding kinetics over its cross-linked counterpart. The rate of nitric oxide binding to the oxidized form of poly alpha-DBBF shows little or no change compared to the intramolecularly cross-linked derivative. The reduction of cyanomet poly alpha-DBBF by dithionite is several fold faster than that of HbA0 and alpha-DBBF whereas the slow subsequent cyanide dissociation from the ferrous iron remained unchanged among all proteins. The propensity of poly alpha-DBBF for auto-oxidation is slightly enhanced over alpha-DBBF whereas the extent of oxidative modification by hydrogen peroxide is very similar. Polymerization appears to selectively modify ligand interactions and redox kinetics of the tetrameric cross-linked form which reflects a possibly more open heme pocket. The data suggests that changes in oxygenation properties of hemoglobin brought about by a given modification are not necessarily predictive of other functional changes.

  20. Hemoglobin electrophoresis

    MedlinePlus

    ... is an abnormal form of hemoglobin associated with sickle cell anemia . In people with this condition, the red blood ... symptoms are much milder than they are in sickle cell anemia. Other, less common, abnormal Hb molecules cause other ...

  1. Interactions of human hemoglobin with charged ligand-functionalized iron oxide nanoparticles and effect of counterions

    NASA Astrophysics Data System (ADS)

    Ghosh, Goutam; Panicker, Lata

    2014-12-01

    Human hemoglobin is an important metalloprotein. It has tetrameric structure with each subunit containing a `heme' group which carries oxygen and carbon dioxide in blood. In this work, we have investigated the interactions of human hemoglobin (Hb) with charged ligand-functionalized iron oxide nanoparticles and the effect of counterions, in aqueous medium. Several techniques like DLS and ζ-potential measurements, UV-vis, fluorescence, and CD spectroscopy have been used to characterize the interaction. The nanoparticle size was measured to be in the range of 20-30 nm. Our results indicated the binding of Hb with both positively as well as negatively charged ligand-functionalized iron oxide nanoparticles in neutral aqueous medium which was driven by the electrostatic and the hydrophobic interactions. The electrostatic binding interaction was not seen in phosphate buffer at pH 7.4. We have also observed that the `heme' groups of Hb remained unaffected on binding with charged nanoparticles, suggesting the utility of the charged ligand-functionalized nanoparticles in biomedical applications.

  2. Specific cation effects on hemoglobin aggregation below and at physiological salt concentration.

    PubMed

    Medda, Luca; Carucci, Cristina; Parsons, Drew F; Ninham, Barry W; Monduzzi, Maura; Salis, Andrea

    2013-12-10

    Turbidity titrations are used to study the ion specific aggregation of hemoglobin (Hb) below and physiological salt concentration in the pH range 4.5-9.5. At a salt concentration 50 mM cations promote Hb aggregation according to the order Rb(+) > K(+) ~ Na(+) > Cs(+) > Li(+). The cation series changes if concentration is increased, becoming K(+) > Rb(+) > Na(+) > Li(+) > Cs(+) at 150 mM. We interpret the puzzling series by assuming that the kosmotropic Li(+) will bind to kosmotropic carboxylates groups-according to the law of matching water affinities (LMWA)-whereas the chaotropic Cs(+) will bind to uncharged protein patches due to its high polarizability. In fact, both mechanisms can be rationalized by invoking previously neglected ionic nonelectrostatic forces. This explains both adsorption to uncharged patches and the LMWA as a consequence of the simultaneous action of electrostatic and dispersion forces. The same interpretation applies to anions (with chaotropic anions binding to chaotropic amine groups). The implications extend beyond hemoglobin to other, still unexplained, ion specific effects in biological systems.

  3. The fungicide mancozeb induces toxic effects on mammalian granulosa cells.

    PubMed

    Paro, Rita; Tiboni, Gian Mario; Buccione, Roberto; Rossi, Gianna; Cellini, Valerio; Canipari, Rita; Cecconi, Sandra

    2012-04-15

    The ethylene-bis-dithiocarbamate mancozeb is a widely used fungicide with low reported toxicity in mammals. In mice, mancozeb induces embryo apoptosis, affects oocyte meiotic spindle morphology and impairs fertilization rate even when used at very low concentrations. We evaluated the toxic effects of mancozeb on the mouse and human ovarian somatic granulosa cells. We examined parameters such as cell morphology, induction of apoptosis, and p53 expression levels. Mouse granulosa cells exposed to mancozeb underwent a time- and dose-dependent modification of their morphology, and acquired the ability to migrate but not to proliferate. The expression level of p53, in terms of mRNA and protein content, decreased significantly in comparison with unexposed cells, but no change in apoptosis was recorded. Toxic effects could be attributed, at least in part, to the presence of ethylenthiourea (ETU), the main mancozeb catabolite, which was found in culture medium. Human granulosa cells also showed dose-dependent morphological changes and reduced p53 expression levels after exposure to mancozeb. Altogether, these results indicate that mancozeb affects the somatic cells of the mammalian ovarian follicles by inducing a premalignant-like status, and that such damage occurs to the same extent in both mouse and human GC. These results further substantiate the concept that mancozeb should be regarded as a reproductive toxicant.

  4. The effect of ascetic acid on mammalian cells

    SciTech Connect

    Mariana, Oana C; Trujillo, Antoinette; Sanders, Claire K; Burnett, Kassidy S; Freyer, James P; Mourant, Judith R

    2010-01-01

    Effects of the contrast agent, acetic acid, on mammalian cells are studied using light scattering measurements, viability and fluorescence pH assays. Results depend on whether cells are in PBS or are live and metabolizing. Acetic acid is a contrast agent used to aid the detection of cancerous and precancerous lesions of the uterine cervix. Typically 3% or 5% acetic acid is applied to the swface of the cervix and areas of the tissue that turn 'acetowhite' are considered more likely to be precancerous. The mechanism of action of acetic acid has never been understood in detail, although there are several hypotheses. One is that a decrease in pH causes cytokeratins in epithelial cells to polymerize. We will present data demonstrating that this is not the sole mechanism of acetowhitening. Another hypothesis is that a decrease in pH in the nucleus causes deacetylation of the histones which in turn results in a dense chromatin structure. Relevant to this hypothesis we have measured the internal pH of cells. Additional goals of this work are to understand what physical changes result in acetowhitening, to understand why there is variation in how cells respond to acetic acid, and to investigate how acetowhitening affects the light scatter properties measured by a fiber-optic probe we have developed for cervical cancer diagnostics.

  5. Effects of coiling on the micromechanics of the mammalian cochlea

    PubMed Central

    Cai, Hongxue; Manoussaki, Daphne; Chadwick, Richard

    2005-01-01

    The cochlea transduces sound-induced vibrations in the inner ear into electrical signals in the auditory nerve via complex fluid–structure interactions. The mammalian cochlea is a spiral-shaped organ, which is often uncoiled for cochlear modelling. In those few studies where coiling has been considered, the cochlear partition was often reduced to the basilar membrane only. Here, we extend our recently developed hybrid analytical/numerical micromechanics model to include curvature effects, which were previously ignored. We also use a realistic cross-section geometry, including the tectorial membrane and cellular structures of the organ of Corti, to model the apical and basal regions of a guinea-pig cochlea. We formulate the governing equations of the fluid and solid domains in a curvilinear coordinate system. The WKB perturbation method is used to treat the propagation of travelling waves along the coiled cochlear duct, and the O(1) system of the governing equations is solved in the transverse plane using finite-element analysis. We find that the curvature of the cochlear geometry has an important functional significance; at the apex, it greatly increases the shear gain of the cochlear partition, which is a measure of the bending efficiency of the outer hair cell stereocilia. PMID:16849192

  6. Effects of Tetrodotoxin on the Mammalian Cardiovascular System

    PubMed Central

    Zimmer, Thomas

    2010-01-01

    The human genome encodes nine functional voltage-gated Na+ channels. Three of them, namely Nav1.5, Nav1.8, and Nav1.9, are resistant to nanomolar concentrations of tetrodotoxin (TTX; IC50 ≥ 1 μM). The other isoforms, which are predominantly expressed in the skeletal muscle and nervous system, are highly sensitive to TTX (IC50 ~ 10 nM). During the last two decades, it has become evident that in addition to the major cardiac isoform Nav1.5, several of those TTX sensitive isoforms are expressed in the mammalian heart. Whereas immunohistochemical and electrophysiological methods demonstrated functional expression in various heart regions, the physiological importance of those isoforms for cardiac excitation in higher mammals is still debated. This review summarizes our knowledge on the systemic cardiovascular effects of TTX in animals and humans, with a special focus on cardiac excitation and performance at lower concentrations of this marine drug. Altogether, these data strongly suggest that TTX sensitive Na+ channels, detected more recently in various heart tissues, are not involved in excitation phenomena in the healthy adult heart of higher mammals. PMID:20411124

  7. Effects of lead on delta-aminolevulinic acid dehydratase activity, growth, hemoglobin content, and reproduction in Daphnia magna

    SciTech Connect

    Berglind, R.; Dave, G.; Sjoebeck, M.L.

    1985-04-01

    The effects of continuous exposure to lead for various periods and recovery in clean water on delta-aminolevulinic acid dehydratase (ALA-D) activity, hemoglobin content, growth, and reproduction were studied in Daphnia magna. Steady-state inhibition of ALA-D activity was reached within 2 days in 16, 64, and 256 micrograms Pb liter-1, but restoration in clean water was prolonged in relation to previous exposure. In spite of the inhibition of ALA-D activity hemoglobin content increased after 2 days in 16 and 24 micrograms Pb liter-1. Furthermore, hemoglobin content in previously exposed animals increased during recovery in clean water. Maximum hemoglobin content (2.9 times control value) was found after 2 days recovery of animals exposed to 64 micrograms Pb liter-1. These findings suggest that some enzyme(s) other than ALA-D in the biosynthetic pathway of hemoglobin formation is (are) more sensitive to lead. Growth, in contrast to reproduction, was stimulated by low concentrations of lead (less than 64 micrograms Pb liter-1), although in 256 micrograms Pb liter-1 growth was also significantly impaired. After 19 days the 16 and 50% reproductive impairment concentrations were less than or equal to 1 and 10 micrograms Pb liter-1, respectively.

  8. Therapeutic effect of Colla corii asini on improving anemia and hemoglobin compositions in pregnant women with thalassemia.

    PubMed

    Li, Yanfang; He, Hui; Yang, Lilin; Li, Xiangyi; Li, Daocheng; Luo, Songping

    2016-11-01

    Currently there is no consensus on treating anemia in pregnant thalassemia patients. In China, Colla corii asini (CCA) has been widely used for treating anemia for more than 2000 years. However, its clinical application in the thalassemia population is limited by a lack of quantitative evidence. The present study aims to investigate the therapeutic effect of CCA in increasing hemoglobin (Hb) concentration and improving abnormal hemoglobin compositions in pregnant patients with β-thalassemia. Seventy-two pregnant patients who met inclusion criteria were randomly assigned to either the treatment group or control group. Patients in the treatment group were given 15 g of CCA, while the control group were observed and followed up without any treatment. Levels of Hb, serum iron (SI), serum ferritin (SF) and three types of Hb components [adult hemoglobin (HbA), fetal hemoglobin (HbF), minor adult hemoglobin (HbA2)] were measured before and after treatment. Treatment with CCA led to a significant increase of Hb. The major Hb component induced by CCA was HbA, while levels of both HbA2 and HbF dropped after treatment. CCA treatment significantly increased SI, while SF remained unaffected. Our data suggest that CCA can improve anemia and optimize Hb components in pregnant patients with thalassemia without affecting iron reserves.

  9. Effect of altitude on oxygen binding by hemoglobin and on organic phosphate levels

    PubMed Central

    Lenfant, Claude; Torrance, John; English, Eugenia; Finch, Clement A.; Reynafarje, Cesar; Ramos, Jose; Faura, Jose

    1968-01-01

    The relationship between oxygen dissociation and 2,3-diphosphoglycerate (2,3-DPG) in the red cell has been studied in subjects moving from low to high altitude and vice versa. Within 24 hr following the change in altitude there was a change in hemoglobin affinity for oxygen; this modification therefore represents an important rapid adaptive mechanism to anoxia. A parallel change occurred in the organic phosphate content of the red cell. While this study does not provide direct evidence of a cause-effect relationship, the data strongly suggest that with anoxia, the observed rise in organic phosphate content of the red cell is responsible for increased availability of oxygen to tissues. Images PMID:5725278

  10. The fungicide mancozeb induces toxic effects on mammalian granulosa cells

    SciTech Connect

    Paro, Rita; Tiboni, Gian Mario; Buccione, Roberto; Rossi, Gianna; Cellini, Valerio; Canipari, Rita; Cecconi, Sandra

    2012-04-15

    The ethylene-bis-dithiocarbamate mancozeb is a widely used fungicide with low reported toxicity in mammals. In mice, mancozeb induces embryo apoptosis, affects oocyte meiotic spindle morphology and impairs fertilization rate even when used at very low concentrations. We evaluated the toxic effects of mancozeb on the mouse and human ovarian somatic granulosa cells. We examined parameters such as cell morphology, induction of apoptosis, and p53 expression levels. Mouse granulosa cells exposed to mancozeb underwent a time- and dose-dependent modification of their morphology, and acquired the ability to migrate but not to proliferate. The expression level of p53, in terms of mRNA and protein content, decreased significantly in comparison with unexposed cells, but no change in apoptosis was recorded. Toxic effects could be attributed, at least in part, to the presence of ethylenthiourea (ETU), the main mancozeb catabolite, which was found in culture medium. Human granulosa cells also showed dose-dependent morphological changes and reduced p53 expression levels after exposure to mancozeb. Altogether, these results indicate that mancozeb affects the somatic cells of the mammalian ovarian follicles by inducing a premalignant-like status, and that such damage occurs to the same extent in both mouse and human GC. These results further substantiate the concept that mancozeb should be regarded as a reproductive toxicant. Highlights: ► The fungicide mancozeb affects oocyte spindle morphology and fertilization rate. ► We investigated the toxic effects of mancozeb on mouse and human granulosa cells. ► Granulosa cells modify their morphology and expression level of p53. ► Mancozeb induces a premalignant-like status in exposed cells.

  11. Effect of Iron Deficiency Anemia on Hemoglobin A1c Levels

    PubMed Central

    Sinha, Nitin; Mishra, T.K.; Singh, Tejinder

    2012-01-01

    Background Iron deficiency anemia is the most common form of anemia in India. Hemoglobin A1c (HbA1c) is used in diabetic patients as an index of glycemic control reflecting glucose levels of the previous 3 months. Like blood sugar levels, HbA1c levels are also affected by the presence of variant hemoglobins, hemolytic anemias, nutritional anemias, uremia, pregnancy, and acute blood loss. However, reports on the effects of iron deficiency anemia on HbA1c levels are inconsistent. We conducted a study to analyze the effects of iron deficiency anemia on HbA1c levels and to assess whether treatment of iron deficiency anemia affects HbA1c levels. Methods Fifty patients confirmed to have iron deficiency anemia were enrolled in this study. HbA1c and absolute HbA1c levels were measured both at baseline and at 2 months after treatment, and these values were compared with those in the control population. Results The mean baseline HbA1c level in anemic patients (4.6%) was significantly lower than that in the control group (5.5%, p<0.05). A significant increase was observed in the patients' absolute HbA1c levels at 2 months after treatment (0.29 g/dL vs. 0.73 g/dL, p<0.01). There was a significant difference between the baseline values of patients and controls (0.29 g/dL vs. 0.74 g/dL, p<0.01). Conclusions In contrast to the observations of previous studies, ours showed that HbA1c levels and absolute HbA1c levels increased with treatment of iron deficiency anemia. This could be attributable to nutritional deficiency and/or certain unknown variables. Further studies are warranted. PMID:22259774

  12. The effects of stroma-free and dextran-conjugated hemoglobin on hemodynamics and carotid blood flow in hemorrhaged guinea pigs.

    PubMed

    Caron, A; Menu, P; Faivre-Fiorina, B; Labrude, P; Vigneron, C

    1999-01-01

    Hemoglobin solutions are potential resuscitative fluids with volume expanding and oxygen delivery abilities developed to reduce the use of blood transfusion. Most hemoglobin solutions in clinical trials increase transiently arterial pressure by inhibiting nitric oxide-dependent vasodilation. Our objective was to compare the effects on central hemodynamics and carotid blood flow of two hemoglobin solutions after resuscitation from hemorrhage in anesthetized guinea pigs. After anesthesia and instrumentation, severe hemorrhage was induced by withdrawing 50% of the blood volume. Resuscitation was performed after 15 min of hypovolemia with 5% albumin, stroma-free hemoglobin, or hemoglobin conjugated to dextran-benzenetetracarboxylate (Dex-BTC-Hb). The mean arterial pressure (MAP), carotid blood flow (CBF), vascular resistance index and heart rate (HR) were monitored for 3 hours after resuscitation. After hemorrhage, MAP and CBF dropped to 57.6 +/- 4.4% and 58.9 +/- 3.7% of control values respectively. Albumin failed to maintain hemodynamics in the decompensatory phase of shock. Both hemoglobin solutions gave rise to a transient increase in MAP (35%); stroma-free hemoglobin increased the CBF (150%) and resistance index (24%) whereas Dex-BTC-Hb had no effect on CBF and vascular resistances. None of the solutions affected the HR. Modified hemoglobin has attenuated effects on CBF and resistance index compared to stroma-free hemoglobin. This may be due to a balance between the stimulation of nitric oxide synthesis by shear-stress and the inhibition of vasodilation by nitric oxide trapping.

  13. Effects of extreme hemodilution with hemoglobin-based O2 carriers on microvascular pressure.

    PubMed

    Cabrales, Pedro; Tsai, Amy G; Winslow, Robert M; Intaglietta, Marcos

    2005-05-01

    A surface-modified polyethylene glycol-conjugated human hemoglobin (MP4) and alpha alpha-cross-linked human hemoglobin (alpha alpha Hb) were used to restore oxygen carrying capacity in conditions of extreme hemodilution (hematocrit 11%) in the hamster window model preparation. Changes in microvascular function were analyzed in terms of effects on capillary pressure and functional capillary density (FCD). MP4, at 1.0 +/- 0.2 g/dl blood concentration, significantly lowered mean arterial pressure (MAP) below baseline (99.6 +/- 7.6 mmHg) to 82.4 +/- 6.9 mmHg (P < 0.05) and decreased of FCD to 70 +/- 9%. alpha alpha Hb caused a greater recovery in MAP to 94.4 +/- 6.2 mmHg and lowered FCD to 62 +/- 8%. However, differences between alpha alpha Hb and MP4 in FCD were not statistically significant. Capillary pressures were in the ranges of 17-21 mmHg for MP4 and 15-19 mmHg for alpha alpha Hb, with both significantly lower than baseline (P < 0.05). Pressure in 80-microm-diameter arterioles was significantly increased with alpha alpha Hb relative to MP4 (P < 0.05). These results were compared with previous findings on the relation between capillary pressure and FCD; they supported the concept of a relationship between FCD and capillary pressure. Measurement of changes in arteriolar diameter, microvascular blood flow, and FCD show that there was no statistical difference between using alpha alpha Hb and MP4 in extreme hemodilution. Microvascular resistance in arterioles with a diameter range of 70-80 microm showed an increase relative to control with alpha alpha Hb, whereas MP4 caused a decrease.

  14. Comparative In Vivo Effects of Hemoglobin-Based Oxygen Carriers (HBOC) with Varying Prooxidant and Physiological Reactivity

    PubMed Central

    Roman, Ioana; Sevastre, Bogdan; Hathazi, Denisa; Scurtu, Florina; Damian, Grigore; Silaghi-Dumitrescu, Radu

    2016-01-01

    A series of hemoglobin-based oxygen carrier candidates (HBOC), previously noted for their differences in prooxidative and physiological reactivity, were compared in terms of the negative effects displayed upon injection in Wistar rats. At the concentrations tested, antioxidant strategies based on albumin as well as based on rubrerythrin appear to offer observable physiological advantages. PMID:27097326

  15. Comparative In Vivo Effects of Hemoglobin-Based Oxygen Carriers (HBOC) with Varying Prooxidant and Physiological Reactivity.

    PubMed

    Toma, Vlad Al; Farcaș, Anca D; Roman, Ioana; Sevastre, Bogdan; Hathazi, Denisa; Scurtu, Florina; Damian, Grigore; Silaghi-Dumitrescu, Radu

    2016-01-01

    A series of hemoglobin-based oxygen carrier candidates (HBOC), previously noted for their differences in prooxidative and physiological reactivity, were compared in terms of the negative effects displayed upon injection in Wistar rats. At the concentrations tested, antioxidant strategies based on albumin as well as based on rubrerythrin appear to offer observable physiological advantages.

  16. Effect of the N-terminal residues on the quaternary dynamics of human adult hemoglobin

    NASA Astrophysics Data System (ADS)

    Chang, Shanyan; Mizuno, Misao; Ishikawa, Haruto; Mizutani, Yasuhisa

    2016-05-01

    The protein dynamics of human hemoglobin following ligand photolysis was studied by time-resolved resonance Raman spectroscopy. The time-resolved spectra of two kinds of recombinant hemoglobin expressed in Escherichia coli, normal recombinant hemoglobin and the α(V1M)/β(V1M) double mutant, were compared with those of human adult hemoglobin (HbA) purified from blood. A frequency shift of the iron-histidine stretching [ν(Fe-His)] band was observed in the time-resolved spectra of all three hemoglobin samples, indicative of tertiary and quaternary changes in the protein following photolysis. The spectral changes of the α(V1M)/β(V1M) double mutant were distinct from those of HbA in the tens of microseconds region, whereas the spectral changes of normal recombinant hemoglobin were similar to those of HbA isolated from blood. These results demonstrated that a structural change in the N-termini is involved in the second step of the quaternary structure change of hemoglobin. We discuss the implications of these results for understanding the allosteric pathway of HbA.

  17. Interaction between hypericin and hemoglobin.

    PubMed

    Vardapetyan, H R; Martirosyan, A S; Tiratsuyan, S G; Hovhannisyan, A A

    2010-10-05

    In the present work the hypericin interaction with hemoglobin was studied by absorption and fluorescence spectroscopy both under incubation in dark and visible light exposure. An absorption reduction in Soret band of hemoglobin (407 nm) was revealed under the photodynamic influence and incubation in dark with hypericin that had hypericin concentration and time dependent manner. Hypericin reduced the intensity of the hemoglobin emission peaks at 334 and 421 nm, correlating with hypericin concentration, incubation and irradiation time. An obvious increase in electrophoretic mobility of hemoglobin was observed under the incubation with hypericin. Simultaneously, a partial conversion of hemoglobin to met-hemoglobin and a pH decrease in hemoglobin solution were detected. Structural changes of hemoglobin caused by hypericin were accompanied by a change in peroxidase activity of the protein. Thus under the hypericin influence hemoglobin properties as a hydrogen peroxide detector could be improved and an effective determination of peroxide formation could be achieved. This makes hemoglobin an attractive 'recognition' element for construction of third-generation biosensors.

  18. Alkaline Bohr effect of bird hemoglobins: the case of the flamingo.

    PubMed

    Sanna, Maria Teresa; Manconi, Barbara; Podda, Gabriella; Olianas, Alessandra; Pellegrini, Mariagiuseppina; Castagnola, Massimo; Messana, Irene; Giardina, Bruno

    2007-08-01

    The hemoglobin (Hb) substitution His-->Gln at position alpha89, very common in avian Hbs, is considered to be responsible for the weak Bohr effect of avian Hbs. Phoenicopterus ruber ruber is one of the few avian Hbs that possesses His at alpha89, but it has not been functionally characterized yet. In the present study the Hb system of the greater flamingo (P. ruber roseus), a bird that lives in Mediterranean areas, has been investigated to obtain further insight into the role played by the alpha89 residue in determining the strong reduction of the Bohr effect. Functional analysis of the two purified Hb components (HbA and HbD) of P. ruber roseus showed that both are characterized by high oxygen affinity in the absence of organic phosphates, a strong modulating effect of inositol hexaphosphate, and a reduced Bohr effect. Indeed, in spite of the close phylogenetic relationship between the two flamingo species, structural analysis based on tandem mass spectrometry of the alpha(A) chain of P. ruber roseus Hb showed that a Gln residue is present at position alpha89.

  19. Effects of Iron Supplementation and Activity on Serum Iron Depletion and Hemoglobin Levels in Female Athletes

    ERIC Educational Resources Information Center

    Cooter, G. Rankin; Mowbray, Kathy W.

    1978-01-01

    Research revealed that a four-month basketball training program did not significantly alter serum iron, total iron binding capacity, hemoglobin, and percent saturation levels in female basketball athletes. (JD)

  20. Effect of succinic acid monoethyl ester on hemoglobin glycation and tail tendon collagen properties in type 2 diabetic rats.

    PubMed

    Saravanan, Ramalingam; Pari, Leelavinothan

    2008-06-01

    Succinic acid monoethyl ester (EMS) was recently proposed as an insulinotropic agent for the treatment of type 2 diabetes. The aim of the study was to investigate the effect of EMS and metformin administration on tail collagen content and its characteristics in streptozotocin-nicotinamide-induced type 2 diabetic rats. EMS was administered intraperitoneally for 30 days to normal and diabetic rats. In the diabetic rats, a significant increase in the levels of glucose, glycated hemoglobin, hydroxyproline, collagen content, extent glycation, fluorescence, neutral salt, acid and pepsin soluble collagen content was absorbed with a significant decrease in the level of insulin, hemoglobin in streptozotocin-nicotinamide diabetic rats. Moreover, a daily administration of nonglucidic nutrient EMS and metformin significantly decreased the levels of glucose, glycated hemoglobin, hydroxyproline, collagen content, extent glycation, fluorescence, neutral salt, acid and pepsin soluble collagen content, whereas it increased insulin, hemoglobin levels in diabetic rats. The positive influence of nonglucidic nutrient on both collagen content and its properties suggests a potential mechanism for the ability of EMS to delay diabetic complications.

  1. Effects of pharmacological ascorbate on hemoglobin-induced cancer cell proliferation.

    PubMed

    Lu, Naihao; Ding, Yun; Tian, Rong; Yang, Zhen; Chen, Jianfa; Peng, Yi-Yuan

    2016-11-01

    The high heme content in red meat is associated with an increased risk of developing cancer. Pharmacologic concentrations of ascorbate can specifically kill a wide range of cancer cells. In this study, the impact of ascorbate at pharmacologic concentrations on hemoglobin (Hb)-modulated human hepatoma HepG2 cell survival was investigated. It was found that HepG2 cells were proliferated by Hb (5-25μM), but killed by high pharmacologic concentrations of ascorbate (2-10mM). Although ascorbate at the low pharmacologic concentration (0.5mM) alone exhibited insignificant effect on cell viability, it effectively inhibited Hb (10μM)-induced cancer cell proliferation. The mechanism of this cytotoxicity was based on the production of extracellular H2O2 and involved transition iron. The influence of ascorbate on Hb-dependent redox reactions (i.e. the oxidative stability of Hb and its cytotoxic ferryl intermediate) was further investigated to illustrate the reaction mechanism of ascorbate toxicity, where H2O2 was generated in the reaction of ascorbate with Hb. Furthermore, circular dichroism demonstrated no significant change in the secondary structure of Hb after ascorbate addition and molecular docking revealed binding modes of ascorbate with Hb. These results demonstrated that ascorbate could possess anti-cancer activity through interfering in Hb-dependent redox reactions.

  2. Clinical Course of Two Children with Unstable Hemoglobins: The Effect of Hydroxyurea Therapy.

    PubMed

    Loovers, Harriët M; Tamminga, Nienke; Mulder, André B; Tamminga, Rienk Y J

    2016-09-01

    Case reports on the effect of hydroxyurea (HU) therapy for unstable hemoglobins (Hbs) are sparse; only three adult cases have been reported. We report for the first time on the effect of HU therapy in children carrying unstable Hbs. The first case concerns a female child with a familial history of chronic hemolytic anemia. She was diagnosed with Hb Volga (HBB: c.83C>A) at the age of 7 months. At age 6, treatment options were reconsidered due to increasing fatigue and decreasing Hb concentration. The second case also concerns a female child with chronic hemolytic anemia and icterus since the age of 5. She was diagnosed with Hb Köln (HBB: c.295G>A) at the age of 9. At age 10, treatment options were reconsidered due to decreased general condition and poor school performance. Both children were started on HU therapy. The child with Hb Volga showed reduced clinical symptoms and increased average Hb concentrations. She has been on HU therapy for over 7 years at preparation of this manuscript. The child with Hb Köln showed decreasing Hb concentrations upon start of therapy; clinical symptoms did not improve. Therapy was discontinued after 3½ months. The Hb Volga case report suggests that HU therapy could improve clinical symptoms in some patients with unstable Hbs. Based on these and previously published cases, it was speculated that response can be predicted by the percentage of Hb F and reticulocyte counts.

  3. Renal Handling of Circulating and Renal-Synthesized Hepcidin and Its Protective Effects against Hemoglobin-Mediated Kidney Injury.

    PubMed

    van Swelm, Rachel P L; Wetzels, Jack F M; Verweij, Vivienne G M; Laarakkers, Coby M M; Pertijs, Jeanne C L M; van der Wijst, Jenny; Thévenod, Frank; Masereeuw, Rosalinde; Swinkels, Dorine W

    2016-09-01

    Urinary hepcidin may have protective effects against AKI. However, renal handling and the potential protective mechanisms of hepcidin are not fully understood. By measuring hepcidin levels in plasma and urine using mass spectrometry and the kidney using immunohistochemistry after intraperitoneal administration of human hepcidin-25 (hhep25) in C57Bl/6N mice, we showed that circulating hepcidin is filtered by the glomerulus and degraded to smaller isoforms detected in urine but not plasma. Moreover, hepcidin colocalized with the endocytic receptor megalin in proximal tubules, and compared with wild-type mice, megalin-deficient mice showed higher urinary excretion of injected hhep25 and no hepcidin staining in proximal tubules that lack megalin. This indicates that hepcidin is reaborbed in the proximal tubules by megalin dependent endocytosis. Administration of hhep25 concomitant with or 4 hours after a single intravenous dose of hemoglobin abolished hemoglobin-induced upregulation of urinary kidney injury markers (NGAL and KIM-1) and renal Interleukin-6 and Ngal mRNA observed 24 hours after administration but did not affect renal ferroportin expression at this point. Notably, coadministration of hhep25 and hemoglobin but not administration of either alone greatly increased renal mRNA expression of hepcidin-encoding Hamp1 and hepcidin staining in distal tubules. These findings suggest a role for locally synthesized hepcidin in renal protection. Our observations did not support a role for ferroportin in hhep25-mediated protection against hemoglobin-induced early injury, but other mechanisms of cellular iron handling may be involved. In conclusion, our data suggest that both systemically delivered and locally produced hepcidin protect against hemoglobin-induced AKI.

  4. Salt, phosphate and the Bohr effect at the hemoglobin beta chain C terminus studied by hydrogen exchange.

    PubMed

    Louie, G; Englander, J J; Englander, S W

    1988-06-20

    Hydrogen exchange experiments using functional labeling and fragment separation methods were performed to study interactions at the C terminus of the hemoglobin beta subunit that contribute to the phosphate effect and the Bohr effect. The results show that the H-exchange behavior of several peptide NH at the beta chain C terminus is determined by a transient, concerted unfolding reaction involving five or more residues, from the C-terminal His146 beta through at least Ala142 beta, and that H-exchange rate can be used to measure the stabilization free energy of interactions, both individually and collectively, at this locus. In deoxy hemoglobin at pH 7.4 and 0 degrees C, the removal of 2,3-diphosphoglycerate (DPG) or pyrophosphate (loss of a salt to His143 beta) speeds the exchange of the beta chain C-terminal peptide NH protons by 2.5-fold (at high salt), indicating a destabilization of the C-terminal segment by 0.5 kcal of free energy. Loss of the His146 beta 1 to Asp94 beta 1 salt link speeds all these protons by 6.3-fold, indicating a bond stabilization free energy of 1.0 kcal. When both these salt links are removed together, the effect is found to be strictly additive; all the protons exchange faster by 16-fold indicating a loss of 1.5 kcal in stabilization free energy. Added salt is slightly destabilizing when DPG is present but provides some increased stability, in the 0.2 kcal range, when DPG is absent. The total allosteric stabilization energy at each beta chain C terminus in deoxy hemoglobin under these conditions is measured to be 3.8 kcal (pH 7.4, 0 degrees C, with DPG). In oxy hemoglobin at pH 7.4 and 0 degrees C, stability at the beta chain C terminus is essentially independent of salt concentration, and the NES modification, which in deoxy hemoglobin blocks the His146 beta to Asp94 beta salt link, has no destabilizing effect, either at high or low salt. These results appear to show that the His146 beta salt link, which participates importantly in the

  5. The Bohr effect of hemoglobin intermediates and the role of salt bridges in the tertiary/quaternary transitions.

    PubMed

    Russo, R; Benazzi, L; Perrella, M

    2001-04-27

    Understanding mechanisms in cooperative proteins requires the analysis of the intermediate ligation states. The release of hydrogen ions at the intermediate states of native and chemically modified hemoglobin, known as the Bohr effect, is an indicator of the protein tertiary/quaternary transitions, useful for testing models of cooperativity. The Bohr effects due to ligation of one subunit of a dimer and two subunits across the dimer interface are not additive. The reductions of the Bohr effect due to the chemical modification of a Bohr group of one and two alpha or beta subunits are additive. The Bohr effects of monoliganded chemically modified hemoglobins indicate the additivity of the effects of ligation and chemical modification with the possible exception of ligation and chemical modification of the alpha subunits. These observations suggest that ligation of a subunit brings about a tertiary structure change of hemoglobin in the T quaternary structure, which breaks some salt bridges, releases hydrogen ions, and is signaled across the dimer interface in such a way that ligation of a second subunit in the adjacent dimer promotes the switch from the T to the R quaternary structure. The rupture of the salt bridges per se does not drive the transition.

  6. Effects of Stroma Free Hemoglobin on Blood Pressure and Renal Function in the Hypotensive Rat: Potential Role of Nitric Oxide Inactivation by Hemoglobin

    DTIC Science & Technology

    2007-11-02

    METHODS Male Sprague-Dawley rats ( Charles River , Wilmington, MA), weighing between 250-350g were used for all experiments. Rats were fed regular Purina...BONAVENTURA. Cell-free hemoglobin reverses the endotoxin mediated hyporesponsivity of rat aortic rings to a-adrenergic agents. Biochem. Biophys

  7. Synergistic Effects of Hemoglobin and Tumor Perfusion on Tumor Control and Survival in Cervical Cancer

    SciTech Connect

    Mayr, Nina A. Wang, Jian Z.; Zhang Dongqing; Montebello, Joseph F.; Grecula, John C.; Lo, Simon S.; Fowler, Jeffery M.; Yuh, William T.C.

    2009-08-01

    Purpose: The tumor oxygenation status is likely influenced by two major factors: local tumor blood supply (tumor perfusion) and its systemic oxygen carrier, hemoglobin (Hgb). Each has been independently shown to affect the radiotherapy (RT) outcome in cervical cancer. This study assessed the effect of local tumor perfusion, systemic Hgb levels, and their combination on the treatment outcome in cervical cancer. Methods and Materials: A total of 88 patients with cervical cancer, Stage IB2-IVA, who were treated with RT/chemotherapy, underwent serial dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) before RT, at 20-22 Gy, and at 45-50 Gy. The DCE-MRI perfusion parameters, mean and lowest 10th percentile of the signal intensity distribution in the tumor pixels, and the Hgb levels, including pre-RT, nadir, and mean Hgb (average of weekly Hgb during RT), were correlated with local control and disease-specific survival. The median follow-up was 4.6 years. Results: Local recurrence predominated in the group with both a low mean Hgb (<11.2 g/dL) and low perfusion (lowest 10th percentile of signal intensity <2.0 at 20-22 Gy), with a 5-year local control rate of 60% vs. 90% for all other groups (p = .001) and a disease-specific survival rate of 41% vs. 72% (p = .008), respectively. In the group with both high mean Hgb and high perfusion, the 5-year local control rate and disease-specific survival rate was 100% and 78%, respectively. Conclusion: These results suggest that the compounded effects of Hgb level and tumor perfusion during RT influence the radioresponsiveness and survival in cervical cancer patients. The outcome was worst when both were impaired. The management of Hgb may be particularly important in patients with low tumor perfusion.

  8. The effects of classic altitude training on hemoglobin mass in swimmers.

    PubMed

    Wachsmuth, N B; Völzke, C; Prommer, N; Schmidt-Trucksäss, A; Frese, F; Spahl, O; Eastwood, A; Stray-Gundersen, J; Schmidt, W

    2013-05-01

    Aim of the study was to determine the influence of classic altitude training on hemoglobin mass (Hb-mass) in elite swimmers under the following aspects: (1) normal oscillation of Hb-mass at sea level; (2) time course of adaptation and de-adaptation; (3) sex influences; (4) influences of illness and injury; (5) interaction of Hb-mass and competition performance. Hb-mass of 45 top swimmers (male 24; female 21) was repeatedly measured (~6 times) over the course of 2 years using the optimized CO-rebreathing method. Twenty-five athletes trained between one and three times for 3-4 weeks at altitude training camps (ATCs) at 2,320 m (3 ATCs) and 1,360 m (1 ATC). Performance was determined by analyzing 726 competitions according to the German point system. The variation of Hb-mass without hypoxic influence was 3.0 % (m) and 2.7 % (f). At altitude, Hb-mass increased by 7.2 ± 3.3 % (p < 0.001; 2,320 m) and by 3.8 ± 3.4 % (p < 0.05; 1,360 m). The response at 2,320 m was not sex-related, and no increase was found in ill and injured athletes (n = 8). Hb-mass was found increased on day 13 and was still elevated 24 days after return (4.0 ± 2.7 %, p < 0.05). Hb-mass had only a small positive effect on swimming performance; an increase in performance was only observed 25-35 days after return from altitude. In conclusion, the altitude (2,320 m) effect on Hb-mass is still present 3 weeks after return, it decisively depends on the health status, but is not influenced by sex. In healthy subjects it exceeds by far the oscillation occurring at sea level. After return from altitude performance increases after a delay of 3 weeks.

  9. Mammalian Toxicity of Munition Compounds. Phase II. Effects of Multiple Doses. Part I. Trinitroglycerin

    DTIC Science & Technology

    1976-02-25

    administrations. In addition, the protective effect of methylene blue on TNG induced methemoglobinemia was investigated. 2. Material and Methods A total of 16 young...hemoglobin concentrations. To study any protective effect on methemogloblu formation, 3 mg/kg of methylene blue (USP water solution for injection) was I9...increased to 3.0% at 2 hours. At this time, 3 mg/kg of methylene blue was injected intravenously to each dog. Instead of increasing quickly to a peak, the

  10. Hemoglobin C disease

    MedlinePlus

    Clinical hemoglobin C ... Hemoglobin C is an abnormal type of hemoglobin, the protein in red blood cells that carries oxygen. It is a type of hemoglobinopathy. The disease is caused by a problem with ...

  11. Recombinant Hemoglobins as Artificial Oxygen Carriers

    PubMed Central

    Fronticelli, Clara; Koehler, Raymond C.; Brinigar, William S.

    2008-01-01

    This paper describes the approaches we have taken to construct a) mutant hemoglobins with different oxygen affinities, and b) mutant hemoglobins and myoglobins that polymerize to high molecular weight aggregates in an effort to prevent extravasation and the associated vasoactivity. In vivo testing indicates that exchange transfusion of polymeric hemoglobins in mice does not result in vasoactivity and that polymeric hemoglobins are effective oxygen carriers to ischemic tissues irrespective of their oxygen affinity and cooperativity. PMID:17364470

  12. Effects of mutations on the molecular dynamics of oxygen escape from the dimeric hemoglobin of Scapharca inaequivalvis.

    PubMed

    Trujillo, Kevin; Papagiannopoulos, Tasso; Olsen, Kenneth W

    2015-01-01

    Like many hemoglobins, the structure of the dimeric hemoglobin from the clam Scapharca inaequivalvis is a "closed bottle" since there is no direct tunnel from the oxygen binding site on the heme to the solvent.  The proximal histidine faces the dimer interface, which consists of the E and F helicies.  This is significantly different from tetrameric vertebrate hemoglobins and brings the heme groups near the subunit interface. The subunit interface is also characterized by an immobile, hydrogen-bonded network of water molecules.  Although there is data which is consistent with the histidine gate pathway for ligand escape, these aspects of the structure would seem to make that pathway less likely. Locally enhanced sampling molecular dynamics are used here to suggest alternative pathways in the wild-type and six mutant proteins. In most cases the point mutations change the selection of exit routes observed in the simulations. Exit via the histidine gate is rarely seem although oxygen molecules do occasionally cross over the interface from one subunit to the other. The results suggest that changes in flexibility and, in some cases, creation of new cavities can explain the effects of the mutations on ligand exit paths.

  13. Effects of simulated weightlessness on mammalian development. Part 1: Development of clinostat for mammalian tissue culture and use in studies on meiotic maturation of mouse oocytes

    NASA Technical Reports Server (NTRS)

    Wolegemuth, D. J.; Grills, G. S.

    1984-01-01

    The effects of weightlessness on three aspects of mammalian reproduction: oocyte development, fertilization, and early embryogenesis was studied. Zero-gravity conditions within the laboratory by construction of a clinostat designed to support in vitro tissue culture were simulated and the effects of simulated weightlessness on meiotic maturation in mammalian oocytes using mouse as the model system were studied. The timing and frequency of germinal vesicule breakdown and polar body extrusion, and the structural and numerical properties of meiotic chromosomes at Metaphase and Metaphase of meiosis are assessed.

  14. Localized Control of Ligand Binding in Hemoglobin: Effect of Tertiary Structure on Picosecond Geminate Recombination

    NASA Astrophysics Data System (ADS)

    Friedman, J. M.; Scott, T. W.; Fisanick, G. J.; Simon, S. R.; Findsen, E. W.; Ondrias, M. R.; MacDonald, V. W.

    1985-07-01

    The picosecond geminate rebinding of molecular oxygen was monitored in a variety of different human, reptilian, and fish hemoglobins. The fast (100 to 200 picoseconds) component of the rebinding is highly sensitive to protein structure. Both proximal and distal perturbations of the heme affect this rebinding process. The rebinding yield for the fast process correlates with the frequency of the stretching motion of the iron-proximal histidine mode (vFe-His) observed in the transient Raman spectra of photodissociated ligated hemoglobins. The high-affinity R-state species exhibit the highest values for vFe-His and the highest yields for fast rebinding, whereas low affinity R-state species and T-state species exhibit lower values of vFe-His and correspondingly reduced yields for this geminate process. These findings link protein control of ligand binding with events at the heme.

  15. Silver-doped calcium phosphate nanoparticles: synthesis, characterization, and toxic effects toward mammalian and prokaryotic cells.

    PubMed

    Peetsch, Alexander; Greulich, Christina; Braun, Dieter; Stroetges, Christian; Rehage, Heinz; Siebers, Bettina; Köller, Manfred; Epple, Matthias

    2013-02-01

    Spherical silver-doped calcium phosphate nanoparticles were synthesized in a co-precipitation route from calcium nitrate/silver nitrate and ammonium phosphate in a continuous process and colloidally stabilized by carboxymethyl cellulose. Nanoparticles with 0.39 wt% silver content and a diameter of about 50-60 nm were obtained. The toxic effects toward mammalian and prokaryotic cells were determined by viability tests and determination of the minimal inhibitory and minimal bactericidal concentrations (MIC and MBC). Three mammalian cells lines, i.e. human mesenchymal stem cells (hMSC) and blood peripheral mononuclear cells (PBMC, monocytes and T-lymphocytes), and two prokaryotic strains, i.e. Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were used. Silver-doped calcium phosphate nanoparticles and silver acetate showed similar effect toward mammalian and prokaryotic cells with toxic silver concentrations in the range of 1-3 μg mL(-1).

  16. When herbivores eat predators: predatory insects effectively avoid incidental ingestion by mammalian herbivores.

    PubMed

    Ben-Ari, Matan; Inbar, Moshe

    2013-01-01

    The direct trophic links between mammalian herbivores and plant-dwelling insects have been practically ignored. Insects are ubiquitous on plants consumed by mammalian herbivores and are thus likely to face the danger of being incidentally ingested by a grazing mammal. A few studies have shown that some herbivorous hemipterans are able to avoid this peril by dropping to the ground upon detecting the heat and humidity on the mammal's breath. We hypothesized that if this risk affects the entire plant-dwelling insect community, other insects that share this habitat are expected to develop similar escape mechanisms. We assessed the ability of three species (adults and larvae) of coccinellid beetles, important aphid predators, to avoid incidental ingestion. Both larvae and adults were able to avoid incidental ingestion effectively by goats by dropping to the ground, demonstrating the importance of this behavior in grazed habitats. Remarkably, all adult beetles escaped by dropping off the plant and none used their functional wings to fly away. In controlled laboratory experiments, we found that human breath caused 60-80% of the beetles to drop. The most important component of mammalian herbivore breath in inducing adult beetles and larvae to drop was the combination of heat and humidity. The fact that the mechanism of dropping in response to mammalian breath developed in distinct insect orders and disparate life stages accentuates the importance of the direct influence of mammalian herbivores on plant-dwelling insects. This direct interaction should be given its due place when discussing trophic interactions.

  17. When Herbivores Eat Predators: Predatory Insects Effectively Avoid Incidental Ingestion by Mammalian Herbivores

    PubMed Central

    Ben-Ari, Matan; Inbar, Moshe

    2013-01-01

    The direct trophic links between mammalian herbivores and plant-dwelling insects have been practically ignored. Insects are ubiquitous on plants consumed by mammalian herbivores and are thus likely to face the danger of being incidentally ingested by a grazing mammal. A few studies have shown that some herbivorous hemipterans are able to avoid this peril by dropping to the ground upon detecting the heat and humidity on the mammal's breath. We hypothesized that if this risk affects the entire plant-dwelling insect community, other insects that share this habitat are expected to develop similar escape mechanisms. We assessed the ability of three species (adults and larvae) of coccinellid beetles, important aphid predators, to avoid incidental ingestion. Both larvae and adults were able to avoid incidental ingestion effectively by goats by dropping to the ground, demonstrating the importance of this behavior in grazed habitats. Remarkably, all adult beetles escaped by dropping off the plant and none used their functional wings to fly away. In controlled laboratory experiments, we found that human breath caused 60–80% of the beetles to drop. The most important component of mammalian herbivore breath in inducing adult beetles and larvae to drop was the combination of heat and humidity. The fact that the mechanism of dropping in response to mammalian breath developed in distinct insect orders and disparate life stages accentuates the importance of the direct influence of mammalian herbivores on plant-dwelling insects. This direct interaction should be given its due place when discussing trophic interactions. PMID:23424674

  18. Delayed treatment of hemoglobin neurotoxicity.

    PubMed

    Regan, Raymond F; Rogers, Bret

    2003-01-01

    Hemoglobin is an oxidative neurotoxin that may contribute to cell injury after CNS trauma and hemorrhagic stroke. Prior studies have demonstrated that concomitant treatment with iron-chelating antioxidants prevents its neurotoxicity. However, the efficacy of these agents when applied hours after hemoglobin has not been determined, and is the subject of the present investigation. Consistent with prior observations, an increase in reactive oxygen species generation, detected by 2',7'-dichlorofluorescin oxidation, was observed when mixed neuronal/astrocyte cultures prepared from mouse cortex were exposed to hemoglobin alone. However, this oxidative stress developed slowly. A significant increase in the dichlorofluorescein signal compared with control, untreated cultures was not observed until four hours after addition of hemoglobin, and was followed by loss of membrane integrity and propidium iodide staining. Treating cultures with the 21-aminosteroid U74500A or the ferric iron chelator deferoxamine four hours after initiating hemoglobin treatment markedly attenuated reactive oxygen species production within 2 h. Continuous exposure to 5 micro M hemoglobin for 24 h resulted in death of about three-quarters of neurons, without injuring astrocytes. Most neuronal loss was prevented by concomitant treatment with U74500A; its effect was not significantly attenuated if treatment was delayed for 2-4 h, and it still prevented over half of neuronal death if treatment was delayed for 8 h. Similar neuroprotection was produced by delayed treatment with deferoxamine or the lipid-soluble iron chelator phenanthroline. None of these agents had any effect on neuronal death when added to cultures 12 h after hemoglobin. These results suggest that hemoglobin is a potent but slowly-acting neurotoxin. The delayed onset of hemoglobin neurotoxicity may make it an attractive target for therapeutic intervention.

  19. Effect of an intravenous iron dextran regimen on iron stores, hemoglobin, and erythropoietin requirements in hemodialysis patients.

    PubMed

    Park, L; Uhthoff, T; Tierney, M; Nadler, S

    1998-05-01

    Iron deficiency is a common cause of delayed or diminished response to erythropoietin (EPO) in hemodialysis patients. Although oral iron is often prescribed to replete iron stores, this approach to iron supplementation may not be adequate with chronic EPO therapy. Intravenous (IV) iron dextran may be an effective alternative approach to replete iron stores and may facilitate more cost-effective use of EPO. The purpose of this study was to evaluate an IV iron dextran regimen that consisted of a loading dose phase followed by monthly maintenance doses of iron dextran. The effect of this regimen on iron stores, hemoglobin, and EPO doses was evaluated. This was an open prospective study in adult hemodialysis patients who were iron deficient as defined by a serum ferritin less than 100 ng/mL or transferrin saturation (TSAT) of less than 20%. Patients were loaded with 1 g iron dextran in five divided doses and then received monthly maintenance doses of 100 mg for the 4-month study period. Values of serum ferritin, TSAT, hemoglobin, and EPO dose were followed for the 4-month study period. Thirty hemodialysis patients receiving EPO were identified as being iron deficient and were enrolled in the study. The mean serum ferritin increased significantly from 49 ng/mL at baseline to 225 ng/mL at the end of the study period (P < 0.0001). Mean TSAT also increased significantly from 27% to 33% (P = 0.002). Values for hemoglobin did not change significantly during the study period; however, there was a significant reduction in EPO dose from a mean baseline dose of 112 U/kg/wk to 88 U/kg/wk at the end of the study period (P = 0.009). Seventeen patients experienced an increase in hemoglobin or a decrease in EPO dose. Economic analysis showed that approximately $580 (Cdn) per patient per year could be saved by use of IV iron dextran. The administration of the IV iron dextran regimen in the iron-deficient hemodialysis population was effective at repleting and maintaining iron stores

  20. The Effect of Hemoglobin Levels on Mortality in Pediatric Patients with Severe Traumatic Brain Injury.

    PubMed

    Yee, Kevin F; Walker, Andrew M; Gilfoyle, Elaine

    2016-01-01

    Objective. There is increasing evidence of adverse outcomes associated with blood transfusions for adult traumatic brain injury patients. However, current evidence suggests that pediatric traumatic brain injury patients may respond to blood transfusions differently on a vascular level. This study examined the influence of blood transfusions and anemia on the outcome of pediatric traumatic brain injury patients. Design. A retrospective cohort analysis of severe pediatric traumatic brain injury (TBI) patients was undertaken to investigate the association between blood transfusions and anemia on patient outcomes. Measurements and Main Results. One hundred and twenty patients with severe traumatic brain injury were identified and included in the analysis. The median Glasgow Coma Scale (GCS) was 6 and the mean hemoglobin (Hgb) on admission was 115.8 g/L. Forty-three percent of patients (43%) received at least one blood transfusion and the mean hemoglobin before transfusion was 80.1 g/L. Multivariable regression analysis revealed that anemia and the administration of packed red blood cells were not associated with adverse outcomes. Factors that were significantly associated with mortality were presence of abusive head trauma, increasing PRISM score, and low GCS after admission. Conclusion. In this single centre retrospective cohort study, there was no association found between anemia, blood transfusions, and hospital mortality in a pediatric traumatic brain injury patient population.

  1. Toxicity and hemodynamic effects after single dose administration of MalPEG-hemoglobin (MP4) in rhesus monkeys.

    PubMed

    Young, Mark A; Malavalli, Ashok; Winslow, Nancy; Vandegriff, Kim D; Winslow, Robert M

    2007-06-01

    Maleimide-polyethylene glycol-modified (MalPEG) hemoglobin, 4.3 g/dL (MP4; Hemospan), is a hemoglobin-based oxygen carrier consisting of human hemoglobin (Hb) modified with maleimide polyethylene glycol. This study evaluates the potential toxicity and hemodynamic actions of a single dose of MP4 administered by exchange transfusion to rhesus monkeys. Monkeys were administered MP4 (21 mL/kg, or approximately 30% of estimated blood volume) or an equivalent volume of lactated Ringer's solution (LR). In the toxicity study, blood samples were obtained predose and 3, 7, and 13 days after dosing for clinical chemistry and hematology. Animals were euthanized for complete necropsy and histopathology on day 3 or day 13. A separate group of animals was used for evaluation of arterial pressure, core temperature, and electrocardiogram, by telemetry, for 7 days after dosing with MP4. The results demonstrate no significant toxicity, with only modest, transient elevation of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) on day 3. Mild anemia caused by hemodilution was observed at each time point in both groups, but to a slightly greater degree in the MP4-treated animals. Histologic observations included foamy or vacuolated macrophages in the spleen and marrow of the sternum, rib, and femur, representing the accumulation of test article or a metabolite. In the telemetry study, no changes occurred in arterial pressure, heart rate, or electrocardiogram attributable to administration of MP4 at any time for 7 days after administration. These results demonstrate that MP4 is safe and is without hemodynamic effects when administered as an exchange transfusion of 30% of estimated blood volume.

  2. Nonlinear photoacoustic spectroscopy of hemoglobin

    NASA Astrophysics Data System (ADS)

    Danielli, Amos; Maslov, Konstantin; Favazza, Christopher P.; Xia, Jun; Wang, Lihong V.

    2015-05-01

    As light intensity increases in photoacoustic imaging, the saturation of optical absorption and the temperature dependence of the thermal expansion coefficient result in a measurable nonlinear dependence of the photoacoustic (PA) signal on the excitation pulse fluence. Here, under controlled conditions, we investigate the intensity-dependent photoacoustic signals from oxygenated and deoxygenated hemoglobin at varied optical wavelengths and molecular concentrations. The wavelength and concentration dependencies of the nonlinear PA spectrum are found to be significantly greater in oxygenated hemoglobin than in deoxygenated hemoglobin. These effects are further influenced by the hemoglobin concentration. These nonlinear phenomena provide insights into applications of photoacoustics, such as measurements of average inter-molecular distances on a nm scale or with a tuned selection of wavelengths, a more accurate quantitative PA tomography.

  3. Nonlinear photoacoustic spectroscopy of hemoglobin

    SciTech Connect

    Danielli, Amos; Maslov, Konstantin; Favazza, Christopher P.; Xia, Jun; Wang, Lihong V.

    2015-05-18

    As light intensity increases in photoacoustic imaging, the saturation of optical absorption and the temperature dependence of the thermal expansion coefficient result in a measurable nonlinear dependence of the photoacoustic (PA) signal on the excitation pulse fluence. Here, under controlled conditions, we investigate the intensity-dependent photoacoustic signals from oxygenated and deoxygenated hemoglobin at varied optical wavelengths and molecular concentrations. The wavelength and concentration dependencies of the nonlinear PA spectrum are found to be significantly greater in oxygenated hemoglobin than in deoxygenated hemoglobin. These effects are further influenced by the hemoglobin concentration. These nonlinear phenomena provide insights into applications of photoacoustics, such as measurements of average inter-molecular distances on a nm scale or with a tuned selection of wavelengths, a more accurate quantitative PA tomography.

  4. Effect of radiofrequency radiation in cultured mammalian cells: A review.

    PubMed

    Manna, Debashri; Ghosh, Rita

    2016-01-01

    The use of mobile phone related technologies will continue to increase in the foreseeable future worldwide. This has drawn attention to the probable interaction of radiofrequency electromagnetic radiation with different biological targets. Studies have been conducted on various organisms to evaluate the alleged ill-effect on health. We have therefore attempted to review those work limited to in vitro cultured cells where irradiation conditions were well controlled. Different investigators have studied varied endpoints like DNA damage, cell cycle arrest, reactive oxygen species (ROS) formation, cellular morphology and viability to weigh the genotoxic effect of such radiation by utilizing different frequencies and dose rates under various irradiation conditions that include continuous or pulsed exposures and also amplitude- or frequency-modulated waves. Cells adapt to change in their intra and extracellular environment from different chemical and physical stimuli through organized alterations in gene or protein expression that result in the induction of stress responses. Many studies have focused on such effects for risk estimations. Though the effects of microwave radiation on cells are often not pronounced, some investigators have therefore combined radiofrequency radiation with other physical or chemical agents to observe whether the effects of such agents were augmented or not. Such reports in cultured cellular systems have also included in this review. The findings from different workers have revealed that, effects were dependent on cell type and the endpoint selection. However, contradictory findings were also observed in same cell types with same assay, in such cases the specific absorption rate (SAR) values were significant.

  5. Hemoglobin Brigham (α2Aβ2100 Pro→Leu). HEMOGLOBIN VARIANT ASSOCIATED WITH FAMILIAL ERYTHROCYTOSIS

    PubMed Central

    Lokich, Jacob J.; Moloney, William C.; Bunn, H. Franklin; Bruckheimer, Sally M.; Ranney, Helen M.

    1973-01-01

    Erythrocytosis associated with the presence of a hemoglobin with increased oxygen affinity has been reported for 10 hemoglobin variants, most of which demonstrate altered electrophoretic mobility. Several members of a family were found to have erythrocytosis, and both the whole blood and the hemoglobin exhibited increased oxygen affinity. Phosphate-free hemoglobin solutions had a normal Bohr effect and reactivity to 2,3-diphosphoglycerate. The electrophoretic properties of the hemoglobin were normal, but on peptide mapping of a tryptic digest of the isolated β-chains, a normal βT11 peptide and an abnormal βT11 with greater Rf were seen. Analysis of the abnormal peptide showed the substitution of leucine for the normal proline at β100 (helical residue G2). The hemoglobin variant, designated Hb Brigham, serves to emphasize the necessity for detailed evaluation of the structure and function of hemoglobin in familial erythrocytosis even with electrophoretically “normal” hemoglobin. PMID:4719677

  6. Electrophysiological effects of risperidone in mammalian cardiac cells.

    PubMed

    Magyar, János; Bányász, Tamás; Bagi, Zsolt; Pacher, Pál; Szentandrássy, Norbert; Fülöp, László; Kecskeméti, Valéria; Nánási, Péter P

    2002-10-01

    In this study, the effects of risperidone, the widely used antipsychotic drug, on isolated canine ventricular myocytes and guinea-pig papillary muscles were analyzed using conventional microelectrode and whole cell voltage-clamp techniques. Risperidone concentration-dependently lengthened action potential duration in guinea-pig papillary muscles (EC(50)=0.29+/-0.02 micro M) and single canine ventricular myocytes (EC(50)=0.48+/-0.14 micro M). This effect was reversible, showed reverse rate dependence, and it was most prominent on the terminal portion of repolarization. No significant effect of risperidone on the resting membrane potential, action potential amplitude or maximum rate of depolarization was observed. In voltage-clamped canine ventricular myocytes risperidone caused concentration-dependent block of the rapid component of the delayed rectifier K(+) current ( I(Kr)), measured as outward current tails at -40 mV, with an IC(50) of 0.92+/-0.26 micro M. Suppression of I(Kr) was not associated with changes in activation or deactivation kinetics. High concentration of risperidone (10 micro M) suppressed also the slow component of the delayed rectifier K(+) current ( I(Ks)) by 9.6+/-1.5% at +50 mV. These effects of risperidone developed rapidly and were readily reversible. Risperidone had no significant effect on the amplitude of other K(+) currents ( I(K1) and I(to)). The inhibition of cardiac I(Kr) current by risperidone may explain the cardiac side-effects observed occasionally with the drug. Our results suggest that risperidone displays class III antiarrhythmic properties, and as such, may produce QTc prolongation, especially in patients with long QT syndrome. Therefore, in psychotic patients having also cardiac disorders, ECG control may be suggested during risperidone therapy.

  7. Collateral effects of antibiotics on mammalian gut microbiomes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antibiotics are an essential component of the modern lifestyle. They improve our lives by treating disease, preventing disease, and in the case of agricultural animals by improving feed efficiency. However, antibiotic usage is not without collateral effects. The development and spread of antibiot...

  8. Oncogenic and mutagenic effects of UV in mammalian cells

    NASA Astrophysics Data System (ADS)

    Yang, T. C.; Mei, M.; George, K. A.; Craise, L. M.

    Ultraviolet light is present in the solar system and can cause major biological effects. The potential cytotoxic, mutagenic, and carcinogenic effects of UV have been studied at cellular and molecular level. Using cultured mouse embryonic fibroblasts (C3H10T1/2), we investigated the induction of mutation and transformation by UV and/or X-rays. Studies were also done with normal human mammary epithelial cells for cell inactivation and mutation induction. Curvlinear dose-response curves were observed for mutation and oncogenic transformation. The interaction between UV and X-rays depends on the sequence of exposure. When UV was given following X-irradiation, there was an additive effect. When UV was given prior to X-irradiation, however, there was a synergistic effect for both cell inactivation and transformation. The basic lesion(s) important for somatic mutation and transformation remains to be determined, and the fundamental mechanism(s) of UV and ionizing radiation interaction remains to be elucidated.

  9. Study of radiation effects on mammalian cells in vitro

    NASA Technical Reports Server (NTRS)

    Sinclair, W. K.

    1968-01-01

    Radiation effect on single cells and cell populations of Chinese hamster lung tissue is studied in vitro. The rate and position as the cell progresses through the generation cycle shows division delay, changes in some biochemical processes in the cell, chromosomal changes, colony size changes, and loss of reproductive capacity.

  10. [EFFECTS OF DIFFERENT CLASSES OF PLANT HORMONES ON MAMMALIAN CELLS].

    PubMed

    Vildanova, M S; Smirnova, E A

    2016-01-01

    Plant hormones are signal molecules of different chemical structure, secreted by plant cells and acting at low concentrations as regulators of plant growth and differentiation. Certain plant hormones are similar to animal hormones or can be produced by animal cells. A number of studies show that the effect of biologically active components of plant origin including plant/phytohormones is much wider than was previously thought, but so far there are no objective criteria for assessing the influence of phytohormones on the physiological state of animal cells. Presented in the survey data show that plant hormones, which have different effects on plant growth and development (jasmonic, abscisic and gibberellic acids), are not neutral to the cells of animal origin, and animal cells response to them may be either positive or negative.

  11. Effect of thymol on calcium handling in mammalian ventricular myocardium.

    PubMed

    Szentandrássy, Norbert; Szigeti, Gyula; Szegedi, Csaba; Sárközi, Sándor; Magyar, János; Bányász, Tamás; Csernoch, László; Kovács, László; Nánási, Péter P; Jóna, István

    2004-01-02

    Concentration-dependent effects of thymol on calcium handling were studied in canine and guinea pig cardiac preparations (Langendorff-perfused guinea pig hearts, canine ventricular trabeculae, canine sarcoplasmic reticular vesicles and single ryanodine receptors). Thymol induced a concentration-dependent negative inotropic action in both canine and guinea pig preparations (EC(50) = 297 +/- 12 microM in dog). However, low concentrations of thymol reduced intracellular calcium transients in guinea pig hearts without decreasing contractility. At higher concentrations both calcium transients and contractions were suppressed. In canine sarcoplasmic reticular vesicles thymol induced rapid release of calcium (V(max) = 0.47 +/- 0.04 nmol s(-1), EC(50) = 258 +/- 21 microM, Hill coefficient = 3.0 +/- 0.54), and decreased the activity of the calcium pump (EC(50) = 253 +/- 4.7 microM, Hill coefficient = 1.62 +/- 0.05). Due to the less sharp concentration-dependence of the ATPase inhibition, this effect was significant from 50 microM, whereas the thymol-induced calcium release only from 100 microM. In single ryanodine receptors incorporated into artificial lipid bilayer thymol induced long lasting openings, having mean open times increased with 3 orders of magnitude, however, the specific conductance of the channel remained unaltered. This effect of thymol was not voltage-dependent and failed to prevent the binding of ryanodine. In conclusion, the negative inotropic action of thymol can be explained by reduction in calcium content of the sarcoplasmic reticulum due to the combination of the thymol-induced calcium release and inhibition of the calcium pump. The calcium-sensitizer effect, observed at lower thymol concentrations, indicates that thymol is likely to interact with the contractile machinery also.

  12. Importance of Many-Body Effects in the Kernel of Hemoglobin for Ligand Binding

    NASA Astrophysics Data System (ADS)

    Weber, Cédric; O'Regan, David D.; Hine, Nicholas D. M.; Littlewood, Peter B.; Kotliar, Gabriel; Payne, Mike C.

    2013-03-01

    We propose a mechanism for binding of diatomic ligands to heme based on a dynamical orbital selection process. This scenario may be described as bonding determined by local valence fluctuations. We support this model using linear-scaling first-principles calculations, in combination with dynamical mean-field theory, applied to heme, the kernel of the hemoglobin metalloprotein central to human respiration. We find that variations in Hund’s exchange coupling induce a reduction of the iron 3d density, with a concomitant increase of valence fluctuations. We discuss the comparison between our computed optical absorption spectra and experimental data, our picture accounting for the observation of optical transitions in the infrared regime, and how the Hund’s coupling reduces, by a factor of 5, the strong imbalance in the binding energies of heme with CO and O2 ligands.

  13. Effective ethanol production from whey powder through immobilized E. coli expressing Vitreoscilla hemoglobin.

    PubMed

    Sar, Taner; Stark, Benjamin C; Yesilcimen Akbas, Meltem

    2017-03-04

    Ethanol production from whey powder was investigated by using free as well as alginate immobilized E. coli and E. coli expressing Vitreoscilla hemoglobin (VHb) in both shake flask and fermenter cultures. Media with varying levels of whey (lactose contents of 3%, 5%, 8% or 15%) and yeast extract (0.3% or 0.5%) were evaluated with fermentation times of 48-96 h. Immobilization and VHb expression resulted in higher ethanol production with all media; the increases ranged from 2% to 89% for immobilization and from 2% to 182% for VHb expression. It was determined that growth medium containing 8% lactose with 0.5% yeast extract yielded the highest ethanol production for free or immobilized strains, with or without VHb expression, in both shake flask and fermenter cultures. Immobilization with alginate was found to be a promising process for ethanol production by VHb-expressing ethanologenic E. coli.

  14. The effect of quaternary structure on the kinetics of conformational changes and nanosecond geminate rebinding of carbon monoxide to hemoglobin

    SciTech Connect

    Murray, L.P.; Hofrichter, J.; Henry, E.R.; Eaton, W.A. ); Ikeda-Saito, Masao; Kitagishi, Keiko; Yonetani, Takashi )

    1988-04-01

    To determine the effect of quaternary structure on the individual kinetic steps in the binding of carbon monoxide to the {alpha} subunit of hemoglobin, time-resolved absorption spectra were measured after photodissociation of carbon monoxide from a hemoglobin tetramer in which cobalt was substituted for iron in the {beta} subunits. Cobalt porphyrins do not bind carbon monoxide. Spectra were measured in the Soret region at room temperature after time delays that varied from a few nanoseconds to the completion of ligand rebinding at about 100 ms. The results show that the liganded molecule is in the R state, but can be almost completely switched into the T state by the allosteric effectors inositol hexaphosphate and bezafibrate. The geminate yield, which is the probability that the ligand rebinds to the heme from within the protein, is found to be 40% for the R state and <1% for the T state. According to the simplest kinetic model, these results indicate that carbon monoxide enters the protein in the R and T quaternary conformations at the same rate, and that the 60-fold decrease in the overall binding rate, of carbon monoxide to the {alpha} subunit in the T state compared to the R state is almost completely accounted for by the decreased probability of binding after the ligand has entered the protein. The results further suggest that the low probability for the T state results from a decreased binding rate to the heme and not from an increased rate of return of the ligand to the solvent.

  15. Some effects of lead at mammalian neuromuscular junction

    SciTech Connect

    Pickett, J.B.; Bornstein, J.C.

    1984-03-01

    The effect of lead on transmitter release was investigated in a rat phrenic nerve-hemidiaphragm preparation using conventional microelectrode techniques. Lead reduced the number of quanta released by a nerve stimulus (m) in a dose-dependent fashion. As extracellular Ca/sup 2 +/ concentration ((Ca/sup 2 +/)/sub 0/) was varied in the absence of lead, a linear relationship between ln(m) and ln((Ca/sup 2 +/)/sub 0/) was obtained. Lead shifted the relationship between ln(m) and ln((Ca/sup 2 +/)/sub 0/) to the right without altering the slope. This suggested lead competed with Ca/sup 2 +/, which was confirmed by using a modified Lineweaver-Burk plot. Lead inhibits Ca/sup 2 +/ entry into frog sympathetic preganglionic nerve terminals, and a similar mechanism may underlie this present finding; such a mechanism, however, could not explain all the observed actions of lead. Lead increased the frequency of spontaneous quantal release in a dose-dependent manner, and 10/sup -4/ M lead doubled the magnitude of facilitation of evoked release seen with five stimuli at 60 Hz. It is suggested that these effects result from inhibition of some, or all, of the nerve terminal's Ca/sup 2 +/ sequestration mechanisms.

  16. Positive Effect of Large Birth Intervals on Early Childhood Hemoglobin Levels in Africa Is Limited to Girls: Cross-Sectional DHS Study

    PubMed Central

    Afeworki, Robel; Smits, Jeroen; Tolboom, Jules; van der Ven, Andre

    2015-01-01

    Background Short birth intervals are independently associated with increased risk of adverse maternal, perinatal, infant and child outcomes. Anemia in children, which is highly prevalent in Africa, is associated with an increased risk of morbidity and mortality. Birth spacing is advocated as a tool to reduce anemia in preschool African children, but the role of gender differences and contextual factors has been neglected. The present study aims to determine to what extent the length of preceding birth interval influences the hemoglobin levels of African preschool children in general, as well as for boys and girls separately, and which contextual factors thereby play a crucial role. Methods and Findings This cross-sectional study uses data from Demographic and Health Surveys (DHS) conducted between 2003 and 2011 in 20 African countries. All preschool children aged 6–59 months with a valid hemoglobin measurement and a preceding birth interval of 7–72 months as well as their corresponding multigravida mothers aged 21–49 years were included in the study. Hemoglobin levels of children and mothers were measured in g/l, while birth intervals were calculated as months difference between consecutive births. Multivariate analyses were done to examine the relationship between length of preceding birth interval and child hemoglobin levels, adjusted for factors at the individual, household, community, district, and country level. A positive linear relationship was observed between birth interval and the 49,260 included children’s hemoglobin level, whereby age and sex of the child, hemoglobin level of the mother, household wealth, mother’s education and urbanization of place of residence also showed positive associations. In the interaction models, the effect of a month increase in birth interval is associated with an average increase of 0.025 g/l in hemoglobin level (P = 0.001) in girls, while for boys the effect was not significant. In addition, for girls, the effect

  17. Effects of methylphenidate (Ritalin) on mammalian myocardial ultrastructure.

    PubMed

    Henderson, T A; Fischer, V W

    1995-01-01

    Previous observations have indicated lamellated ultrastructural lesions in the myocardium of a patient treated with methylphenidate (Ritalin) hydrochloride (MPH). A causal relationship between MPH exposure and these membranous changes was tested in the myocardium of rats and mice. Following injection of varying doses of MPH for different periods, myocardial ultrastructure was examined and lesions were quantified by stereological techniques. Myocardial tissue also was stained using techniques selective for acid phosphatase and for sarcoplasmic reticulum to identify possible pathogenetic mechanisms. MPH induced membrane accumulations and lamellations which were not membrane-bound and did not react for acid phosphatase, but stained positively for sarcoplasmic reticulum. Both lesions were highly focal, surrounded by normal appearing myocardial tissue. Lamellations were evident at the earliest timepoints examined and appeared to occur without lysosomal involvement. Lesions were still apparent 12 weeks after terminating MPH. These data suggest that MPH may have persistent, cumulative effects on the myocardium.

  18. An analysis of particle track effects on solid mammalian tissues

    NASA Technical Reports Server (NTRS)

    Todd, P.; Clarkson, T. W. (Principal Investigator)

    1992-01-01

    Relative biological effectiveness (RBE) and quality factor (Q) at extreme values of linear energy transfer (LET) have been determined on the basis of experiments with single-cell systems and specific tissue responses. In typical single-cell systems, each heavy particle (Ar or Fe) passes through a single cell or no cell. In experiments on animal tissues, however, each heavy particle passes through several cells, and the LET can exceed 200 keV micrometers-1 in every cell. In most laboratory animal tissue systems, however, only a small portion of the hit cells are capable of expressing the end-point being measured, such as cell killing, mutation or carcinogenesis. The following question was therefore addressed: do RBEs and Q factors derived from single-cell experiments properly account for the damage at high LET when multiple cells are hit by HZE tracks? A review is offered in which measured radiation effects and known tissue properties are combined to estimate on the one hand, the number of cells at risk, p3n, per track, where n is the number of cells per track based on tissue and organ geometry, and p3 is the probability that a cell in the track is capable of expressing the experimental end-point. On the other hand, the tissue and single-cell responses are compared by determining the ratio RBE in tissue/RBE in corresponding single cells. Experimental data from the literature indicate that tissue RBEs at very high LET (Fe and Ar ions) are higher than corresponding single-cell RBEs, especially in tissues in which p3n is high.

  19. Effect of Gravity on the Mammalian Cell Deformation

    NASA Technical Reports Server (NTRS)

    Hung, R. J.; Tsao, Y.; Gonda, Steven

    1995-01-01

    The effect of human cell immersed in culture liquid under a micro-gravity environment has been investigated. The study is based on the numerical simulation of the configuration of human cell affected by the time dependent variation of gravity acceleration ranging from 10(exp -3) to 2 g(sub o) (g(sub o) = 9.81 m/s(exp 2)) in 15 seconds. Both the free floating cell and the cell contacted to the upper and lower inclined walls imposed by the time-dependent reduced gravity acceleration are considered in this study. The results show that the cell configuration changes from spherical to horizontally elongated ellipsoid for both the free floating cell and the cell sitting on the lower inclined wall while the cell configuration varies from spherical to vertically elongated ellipsoid for the cell hanging to the upper inclined wall when the gravity acceleration increases. Experimental observations, carried out of human cells exposed to the variation of gravity levels, show that the results of experimental observations agree exactly with the theoretical model computation described in this paper. These results sre significant for humans exposed to the micro-gravity environment.

  20. Biological Effects of Trichoderma harzianum Peptaibols on Mammalian Cells

    PubMed Central

    Peltola, Joanna; Ritieni, Alberto; Mikkola, Raimo; Grigoriev, Pavel A.; Pócsfalvi, Gabriella; Andersson, Maria A.; Salkinoja-Salonen, Mirja S.

    2004-01-01

    Trichoderma species isolated from water-damaged buildings were screened for toxicity by using boar sperm cells as indicator cells. The crude methanolic cell extract from Trichoderma harzianum strain ES39 inhibited the boar sperm cell motility at a low exposure concentration (50% effective concentration, 1 to 5 μg [dry weight] ml of extended boar semen−1). The same exposure concentration depleted the boar sperm cells of NADH2. Inspection of the exposed boar sperm cells by transmission electron microscopy revealed damage to the plasma membrane. By using the black lipid membrane technique, it was shown that the semipurified metabolites (eluted from a SepPak C18 cartridge) of T. harzianum strain ES39 induced voltage-dependent conductivity. The high-performance liquid chromatography-purified metabolites of T. harzianum strain ES39 dissipated the mitochondrial membrane potential (Δψm) of human lung epithelial carcinoma cells (cell line A549). The semipurified metabolites (eluted from a SepPak C18 cartridge) of T. harzianum strain ES39 were analyzed by mass spectrometry (MS). Matrix-assisted laser desorption ionization and nanoflow electrospray ionization MS revealed five major peptaibols, each of which contained 18 residues and had a mass ranging from 1,719 to 1,775 Da. Their partial amino acid sequences were determined by collision-induced dissociation tandem MS. PMID:15294840

  1. Contrasting Effects of Different Mammalian Herbivores on Sagebrush Plant Communities

    PubMed Central

    Veblen, Kari E.; Nehring, Kyle C.; McGlone, Christopher M.; Ritchie, Mark E.

    2015-01-01

    Herbivory by both grazing and browsing ungulates shapes the structure and functioning of terrestrial ecosystems worldwide, and both types of herbivory have been implicated in major ecosystem state changes. Despite the ecological consequences of differences in diets and feeding habits among herbivores, studies that experimentally distinguish effects of grazing from spatially co-occurring, but temporally segregated browsing are extremely rare. Here we use a set of long-term exclosures in northern Utah, USA, to determine how domestic grazers vs. wild ungulate herbivores (including browsers and mixed feeders) affect sagebrush-dominated plant communities that historically covered ~62 million ha in North America. We sampled plant community properties and found that after 22 years grazing and browsing elicited perceptible changes in overall plant community composition and distinct responses by individual plant species. In the woody layer of the plant community, release from winter and spring wild ungulate herbivory increased densities of larger Wyoming big sagebrush (Artemisia tridentata, ssp. wyomingensis) at the expense of small sagebrush, while disturbance associated with either cattle or wild ungulate activity alone was sufficient to increase bare ground and reduce cover of biological soil crusts. The perennial bunchgrass, bottlebrush squirretail (Elymus elymoides), responded positively to release from summer cattle grazing, and in turn appeared to competitively suppress another more grazing tolerant perennial grass, Sandberg’s blue grass (Poa secunda). Grazing by domestic cattle also was associated with increased non-native species biomass. Together, these results illustrate that ungulate herbivory has not caused sagebrush plant communities to undergo dramatic state shifts; however clear, herbivore-driven shifts are evident. In a dry, perennial-dominated system where plant community changes can occur very slowly, our results provide insights into potential long

  2. Contrasting effects of different mammalian herbivores on sagebrush plant communities.

    PubMed

    Veblen, Kari E; Nehring, Kyle C; McGlone, Christopher M; Ritchie, Mark E

    2015-01-01

    Herbivory by both grazing and browsing ungulates shapes the structure and functioning of terrestrial ecosystems worldwide, and both types of herbivory have been implicated in major ecosystem state changes. Despite the ecological consequences of differences in diets and feeding habits among herbivores, studies that experimentally distinguish effects of grazing from spatially co-occurring, but temporally segregated browsing are extremely rare. Here we use a set of long-term exclosures in northern Utah, USA, to determine how domestic grazers vs. wild ungulate herbivores (including browsers and mixed feeders) affect sagebrush-dominated plant communities that historically covered ~62 million ha in North America. We sampled plant community properties and found that after 22 years grazing and browsing elicited perceptible changes in overall plant community composition and distinct responses by individual plant species. In the woody layer of the plant community, release from winter and spring wild ungulate herbivory increased densities of larger Wyoming big sagebrush (Artemisia tridentata, ssp. wyomingensis) at the expense of small sagebrush, while disturbance associated with either cattle or wild ungulate activity alone was sufficient to increase bare ground and reduce cover of biological soil crusts. The perennial bunchgrass, bottlebrush squirretail (Elymus elymoides), responded positively to release from summer cattle grazing, and in turn appeared to competitively suppress another more grazing tolerant perennial grass, Sandberg's blue grass (Poa secunda). Grazing by domestic cattle also was associated with increased non-native species biomass. Together, these results illustrate that ungulate herbivory has not caused sagebrush plant communities to undergo dramatic state shifts; however clear, herbivore-driven shifts are evident. In a dry, perennial-dominated system where plant community changes can occur very slowly, our results provide insights into potential long

  3. Reproducing the Hemoglobin Saturation Profile, a Marker of the Blood Oxygenation Level Dependent (BOLD) fMRI Effect, at the Microscopic Level.

    PubMed

    Hadjistassou, Constantinos; Moyle, Keri; Ventikos, Yiannis

    2016-01-01

    The advent of functional MRI in the mid-1990s has catalyzed progress pertaining to scientific discoveries in neuroscience. With the prospect of elucidating the physiological aspect of the Blood Oxygenation Level Dependent (BOLD) effect we present a computational capillary-tissue system capable of mapping venous hemoglobin saturation- a marker of the BOLD hemodynamic response. Free and facilitated diffusion and convection for hemoglobin and oxygen are considered in the radial and axial directions. Hemoglobin reaction kinetics are governed by the oxyhemoglobin dissociation curve. Brain activation, mimicked by dynamic transitions in cerebral blood velocity (CBv) and oxidative metabolism (CMRO2), is simulated by normalized changes in m = (ΔCBv/CBv)/(ΔCMRO2/CMRO2) of values 2, 3 and 4. Venous hemoglobin saturation profiles and peak oxygenation results, for m = 2, based upon a 50% and a 25% increase in CBv and CMRO2, respectively, lie within physiological limits exhibiting excellent correlation with the BOLD signal, for short-duration stimuli. Our analysis suggests basal CBv and CMRO2 values of 0.6 mm/s and 200 μmol/100g/min. Coupled CBv and CMRO2 responses, for m = 3 and m = 4, overestimate peak hemoglobin saturation, confirming the system's responsiveness to changes in hematocrit, CBv and CMRO2. Finally, factoring in neurovascular effects, we show that no initial dip will be observed unless there is a time delay in the onset of increased CBv relative to CMRO2.

  4. Sulfide-Binding Hemoglobins: Effects of Mutations on Active-Site Flexibility

    PubMed Central

    Fernandez-Alberti, S.; Bacelo, D. E.; Binning, R. C.; Echave, J.; Chergui, M.; Lopez-Garriga, J.

    2006-01-01

    The dynamics of Hemoglobin I (HbI) from the clam Lucina pectinata, from wild-type sperm whale (SW) myoglobin, and from the L29F/H64Q/V68F triple mutant of SW, both unligated and bound to hydrogen sulfide (H2S), have been studied in molecular dynamics simulations. Features that account for differences in H2S affinity among the three have been examined. Our results verify the existence of an unusual heme rocking motion in unligated HbI that can promote the entrance of large ligands such as H2S. The FQF-mutant partially reproduces the amplitude and relative orientation of the motion of HbI's heme group. Therefore, besides introducing favorable electrostatic interactions with H2S, the three mutations in the distal pocket change the dynamic properties of the heme group. The active-site residues Gln-64(E7), Phe-43(CD1), and His-93(F8) are also shown to be more flexible in unligated HbI than in FQF-mutant and SW. Further contributions to H2S affinity come from differences in hydrogen bonding between the heme propionate groups and nearby amino acid residues. PMID:16782787

  5. Effects of indigo carmine intravenous injection on noninvasive and continuous total hemoglobin measurement with using the Revision L sensor.

    PubMed

    Isosu, Tsuyoshi; Obara, Shinju; Hakozaki, Takahiro; Imaizumi, Tsuyoshi; Iseki, Yuzo; Mogami, Midori; Ohashi, Satoshi; Ikegami, Yukihiro; Kurosawa, Shin; Murakawa, Masahiro

    2017-04-01

    The effects of intravenous injection of indigo carmine on noninvasive and continuous total hemoglobin (SpHb) measurement were retrospectively evaluated with the Revision L sensor. The subjects were 18 patients who underwent elective gynecologic surgery under general anesthesia. During surgery, 5 mL of 0.4 % indigo carmine was injected intravenously, and changes in SpHb concentrations between before and after the injection were evaluated. The mean age was 52.4 ± 12.8 years. Before injection, the median SpHb level was 10.1 (range, 6.8-13.4) g/dL. The results demonstrated no change in SpHb concentration between before and after indigo carmine injection as detected by the Revision L sensor. SpHb measurements as determined with the Revision L sensor were not affected, even after the intravenous injection of indigo carmine.

  6. Clinical effectiveness of hemoglobin spray (Granulox®) as adjunctive therapy in the treatment of chronic diabetic foot ulcers

    PubMed Central

    Hunt, Sharon D.; Elg, Fredrik

    2016-01-01

    Introduction Hemoglobin spray (Granulox®) comprises purified hemoglobin and is a novel approach for increasing oxygen availability in the wound bed in diabetic foot ulcer patients. Its mode of action is to bind oxygen from the atmosphere and diffuse it into the wound bed to accelerate wound healing in slow-healing wounds. Patients and methods Wound healing outcomes, that is, wound size, pain, percentage of slough, and exudate levels, were compared retrospectively to a similar cohort of patients treated over the same period the previous year. The same inclusion and exclusion criteria applied to both groups. Results All 20 (100%) hemoglobin spray-treated patients and 15 (75%) control patients experienced some wound healing by week 4, with 5 (25%) and 1 (5%), respectively, achieving complete wound closure. At week 4, mean wound size reduction was 63% in the hemoglobin spray group versus 26% for controls, increasing to 95% reduction at week 28 in the hemoglobin spray group versus 63% for controls (p<0.05 at all timepoints). Hemoglobin spray was associated with substantially lower pain scores using a 10-cm visual analogue scale, with 19/19 patients (100%) being pain-free from week 12 onwards, compared to 6/18 patients (33%) in the control group. At week 28, 2/18 patients (11%) in the control group still had pain. Both groups had similar baseline slough levels, but hemoglobin spray-treated wounds had slough completely eliminated after 4 weeks versus 10% mean reduction in the control group (p<0.001). Hemoglobin spray was associated with markedly reduced exudate levels; within 4 weeks, no patients had high exudate levels in the hemoglobin spray group versus 5 in the control group. Conclusion Standard wound care plus hemoglobin spray results in improvements in wound closure, wound size reduction, pain, slough, and exudate levels compared to control patients for chronic diabetic foot ulcer treatment. PMID:27829487

  7. Development of a simple assay system for protein-stabilizing efficiency based on hemoglobin protection against denaturation and measurement of the cooperative effect of mixing protein stabilizers.

    PubMed

    Chen, Siyu; Manabe, Yoshiyuki; Minamoto, Naoya; Saiki, Naoka; Fukase, Koichi

    2016-10-01

    We have elucidated the cooperative stabilization of proteins by sugars, amino acids, and other protein-stabilizing agents using a new and simple assay system. Our system determines the protein-stabilizing ability of various compounds by measuring their ability to protect hemoglobin from denaturation. Hemoglobin denaturation was readily measured by quantitative changes in its ultraviolet-visible absorption spectrum. The efficiency of our assay was confirmed using various sugars such as trehalose and sucrose that are known to be good protein stabilizers. We have also found that mixtures of two different types of protein stabilizers resulted in a cooperative stabilizing effect on protein.

  8. Effects of Sleep Disorders on Hemoglobin A1c Levels in Type 2 Diabetic Patients

    PubMed Central

    Keskin, Ahmet; Ünalacak, Murat; Bilge, Uğur; Yildiz, Pinar; Güler, Seda; Selçuk, Engin Burak; Bilgin, Muzaffer

    2015-01-01

    Background: Studies have reported the presence of sleep disorders in approximately 50–70% of diabetic patients, and these may contribute to poor glycemic control, diabetic neuropathy, and overnight hypoglycemia. The aim of this study was to determine the frequency of sleep disorders in diabetic patients, and to investigate possible relationships between scores of these sleep disorders and obstructive sleep apnea syndrome (OSAS) and diabetic parameters (fasting blood glucose, glycated hemoglobin A1c [HbA1c], and lipid levels). Methods: We used the Berlin questionnaire (BQ) for OSAS, the Epworth Sleepiness Scale (ESS), and the Pittsburgh Sleep Quality Index (PSQI) to determine the frequency of sleep disorders and their possible relationships with fasting blood glucose, HbA1c, and lipid levels. Results: The study included 585 type 2 diabetic patients admitted to family medicine clinics between October and December 2014. Sleep, sleep quality, and sleep scores were used as the dependent variables in the analysis. The ESS scores showed that 54.40% of patients experienced excessive daytime sleepiness, and according to the PSQI, 64.30% experienced poor-quality sleep. The BQ results indicated that 50.20% of patients were at high-risk of OSAS. HbA1c levels correlated significantly with the ESS and PSQI results (r = 0.23, P < 0.001 and r = 0.14, P = 0.001, respectively), and were significantly higher in those with high-risk of OSAS as defined by the BQ (P < 0.001). These results showed that HbA1c levels were related to sleep disorders. Conclusions: Sleep disorders are common in diabetic patients and negatively affect the control of diabetes. Conversely, poor diabetes control is an important factor disturbing sleep quality. Addressing sleep disturbances in patients who have difficulty controlling their blood glucose has dual benefits: Preventing diabetic complications caused by sleep disturbance and improving diabetes control. PMID:26668142

  9. Effect of dialysis dose and membrane flux on hemoglobin cycling in hemodialysis patients.

    PubMed

    He, Liyu; Fu, Min; Chen, Xian; Liu, Hong; Chen, Xing; Peng, Xiaofei; Liu, Fuyou; Peng, Youming

    2015-04-01

    Many studies found that hemoglobin (Hb) fluctuation was closely related to the prognosis of the maintenance hemodialysis patients. We investigated the association of factors relating dialysis dose and dialyzer membrane with Hb levels. We undertook a randomized clinical trial in 140 patients undergoing thrice-weekly dialysis and assigned patients randomly to a standard or high dose of dialysis; Hb level was measured every month for 12 months. In the standard-dose group, the mean (±SD) urea reduction ratio was 65.1% ± 7.3%, the single-pool Kt/V was 1.26 ± 0.11, and the equilibrated Kt/V was 1.05 ± 0.09; in the high-dose group, the values were 73.5% ± 8.7%, 1.68 ± 0.15, and 1.47 ± 0.11, respectively. The standard deviation (SD) and residual SD (liner regression of Hb) values of Hb were significantly higher in the standard-dose group and low-flux group. The percentage achievement of target Hb in the high-dose dialysis group and high-flux dialyzer group was significantly higher than the standard-dose group and low-flux group, respectively. Patients undergoing hemodialysis thrice weekly appear to have benefit from a higher dialysis dose than that recommended by current KDQQI (Kidney Disease Qutcome Quality Initiative) guidelines or from the use of a high-flux membrane, which is in favor of maintaining stable Hb levels.

  10. Effects of Global Warming on Ancient Mammalian Communities and Their Environments

    PubMed Central

    DeSantis, Larisa R. G.; Feranec, Robert S.; MacFadden, Bruce J.

    2009-01-01

    Background Current global warming affects the composition and dynamics of mammalian communities and can increase extinction risk; however, long-term effects of warming on mammals are less understood. Dietary reconstructions inferred from stable isotopes of fossil herbivorous mammalian tooth enamel document environmental and climatic changes in ancient ecosystems, including C3/C4 transitions and relative seasonality. Methodology/Principal Findings Here, we use stable carbon and oxygen isotopes preserved in fossil teeth to document the magnitude of mammalian dietary shifts and ancient floral change during geologically documented glacial and interglacial periods during the Pliocene (∼1.9 million years ago) and Pleistocene (∼1.3 million years ago) in Florida. Stable isotope data demonstrate increased aridity, increased C4 grass consumption, inter-faunal dietary partitioning, increased isotopic niche breadth of mixed feeders, niche partitioning of phylogenetically similar taxa, and differences in relative seasonality with warming. Conclusion/Significance Our data show that global warming resulted in dramatic vegetation and dietary changes even at lower latitudes (∼28°N). Our results also question the use of models that predict the long term decline and extinction of species based on the assumption that niches are conserved over time. These findings have immediate relevance to clarifying possible biotic responses to current global warming in modern ecosystems. PMID:19492043

  11. Mutagenic effect of a keV range N + beam on mammalian cells

    NASA Astrophysics Data System (ADS)

    Feng, Huiyun; Wu, Lijun; Yu, Lixiang; Han, Wei; Liu, Xuelan; Yu, Zengliang

    2005-07-01

    The radiobiological effects of a keV (5-20 keV) range nitrogen ion (N +) beam on mammalian cells were studied, particularly with regard to the induction of mutation in the cell genome. The experiment demonstrated that the 20 keV N + beam, which resulted in cell death to a certain extent, induced a 2-3 fold increase in the mutation rates at the CD59 gene locus of the mammalian A L cells as compared to the control. Within certain fluence ranges (0-6 × 10 14 N +/cm 2), the cell survival displayed a down-up-down pattern which is similar to the phenomenon known as 'hyper-radiosensitivity' manifested under low-dose irradiation; the CD59 mutation rate firstly showed a gradual rise up to a 3-fold increment above the background level as the ion fluence went up to 4 × 10 14 N +/cm 2, after this peak point however, a downtrend appeared though the ion fluence increased further. It was also observed that the fraction of CD59 mutation bears no proportional relation to ion energy in further experiments of mutation induction by N + beams with the incident energies of 5, 10, 15 and 20 keV at the same fluence of 3 × 10 14 N +/cm 2. Analyses of the deletion patterns of chromosome 11 in CD59- mutants induced by 5-20 keV N + beams showed that these ions did not result in large-size chromosome deletions in this mammalian cell system. A preliminary discussion, suggesting that the mutagenic effect of such low-energy ion influx on mammalian cells could result from multiple processes involving direct collision of particles with cellular DNA, and cascade atomic and molecular reactions due to plentiful primary and secondary particles, was also presented. The study provided the first glimpse into the roles low-energy ions may play in inducing mutagenesis in mammalian cells, and results will be of much value in helping people to understand the contribution of low-energy ions to radiological effects of various ionising radiations.

  12. NIR Raman spectra of whole human blood: Effects of laser-induced and in vitro hemoglobin denaturation

    PubMed Central

    Lemler, P.; Premasiri, W. R.; DelMonaco, A.; Ziegler, L. D.

    2013-01-01

    Care must be exercised in the use of Raman spectroscopy for the identification of blood in forensic applications. The 785 nm excited Raman spectra of dried whole human blood are shown to be exclusively due to oxyhemoglobin (oxyHb) or related hemoglobin denaturation products. Raman spectra of whole blood are reported as a function of incident 785 nm laser power and features attributable to heme aggregates are observed for fluences on the order of 104 W/cm2 and 20 sec signal collection times. In particular, the formation of this local heating induced heme aggregate product is indicated by a red-shifting of several heme porphyrin ring vibrational bands, the appearance of a large broad band at 1248 cm−1, the disappearance of the Fe-O2 stretching and bending bands, and the observation of a large overlapping fluorescence. This denaturation product is also observed in the low power excited Raman spectrum of older ambient air exposed bloodstains (≥ two weeks). The 785 nm excited Raman spectrum of methemoglobin whole blood is reported and increasing amounts of this natural denaturation product can also be identified in dried whole blood Raman spectra particularly when the blood has been stored prior to drying. These results indicate that to use 785 nm excited Raman spectra as an identification methodology for forensic applications to maximum effectiveness, incident laser powers need to be kept low to eliminate variable amounts of heme aggregate spectral components contributing to the signal and the natural aging process of hemoglobin denaturation needs to be accounted for. This also suggests that there is a potential opportunity for 785 nm excited Raman to be a sensitive indicator of dried bloodstain age at crime scenes. PMID:24162820

  13. Heat treatment of human esophageal tissues: Effect on esophageal cancer detection using oxygenated hemoglobin diffuse reflectance ratio

    NASA Astrophysics Data System (ADS)

    Zhao, Q. L.; Guo, Z. Y.; Si, J. L.; Wei, H. J.; Yang, H. Q.; Wu, G. Y.; Xie, S. S.; Guo, X.; Zhong, H. Q.; Li, L. Q.; Li, X. Y.

    2011-03-01

    The main objective of the present work is to study the influence of heat treatment on the esophageal cancer detection using the diffuse reflectance (DR) spectral intensity ratio R540/R575 of oxygenated hemoglobin (HbO2) absorption bands to distinguish the epithelial tissues of normal human esophagus and moderately differentiated esophageal squamous cell carcinoma (ESCC) at different heat treatment temperature of 20, 37, 42, 50, and 60°C, respectively. The DR spectra for the epithelial tissues of the normal esophagus and ESCC in vitro at different heat-treatment temperature in the wavelength range 400-650 nm were measured with a commercial optical fiber spectrometer. The results indicate that the average DR spectral intensity overall enhancement with concomitant increase of heat-treatment temperature for the epithelial tissues of normal esophagus and ESCC, but the average DR spectral intensity for the normal esophageal epithelial tissues is relatively higher than that for ESCC epithelial tissues at the same heat-treatment temperature. The mean R540/R575 ratios of ESCC epithelial tissues were always lower than that of normal esophageal epithelial tissues at the same temperature, and the mean R540/R575 ratios of the epithelial tissues of the normal esophagus and ESCC were decreasing with the increase of different heat-treatment temperatures. The differences in the mean R540/R575 ratios between the epithelial tissues of normal esophagus and ESCC were 13.33, 13.59, 11.76, and 11.11% at different heat-treatment temperature of 20, 37, 42, and 50°C, respectively. These results also indicate that the DR intensity ratio R540/R575 of the hemoglobin bands is a useful tool for discrimination between the epithelial tissues of normal esophagus and ESCC in the temperature range from room temperature to 50°C, but it was non-effective at 60°C or over 60°C.

  14. NIR Raman spectra of whole human blood: effects of laser-induced and in vitro hemoglobin denaturation.

    PubMed

    Lemler, P; Premasiri, W R; DelMonaco, A; Ziegler, L D

    2014-01-01

    Care must be exercised in the use of Raman spectroscopy for the identification of blood in forensic applications. The Raman spectra of dried whole human blood excited at 785 nm are shown to be exclusively due to oxyhemoglobin or related hemoglobin denaturation products. Raman spectra of whole blood are reported as a function of the incident 785-nm-laser power, and features attributable to heme aggregates are observed for fluences on the order of 10(4) W/cm(2) and signal collection times of 20 s. In particular, the formation of this local-heating-induced heme aggregate product is indicated by a redshifting of several heme porphyrin ring vibrational bands, the appearance of a large broad band at 1,248 cm(-1), the disappearance of the Fe-O2 stretching and bending bands, and the observation of a large overlapping fluorescence band. This denaturation product is also observed in the low-power-excitation Raman spectrum of older ambient-air-exposed bloodstains (2 weeks or more). The Raman spectrum of methemoglobin whole blood excited at 785 nm is reported, and increasing amounts of this natural denaturation product can also be identified in Raman spectra of dried whole blood particularly when the blood has been stored prior to drying. These results indicate that to use 785-nm-excitation Raman spectra as an identification method for forensic applications to maximum effect, incident laser powers need to be kept low to eliminate variable amounts of heme aggregate spectral components contributing to the signal and the natural aging process of hemoglobin denaturation needs to be accounted for. This also suggests that there is a potential opportunity for 785-nm-excitation Raman spectra to be a sensitive indicator of the age of dried bloodstains at crime scenes.

  15. Hemoglobins, programmed cell death and somatic embryogenesis.

    PubMed

    Hill, Robert D; Huang, Shuanglong; Stasolla, Claudio

    2013-10-01

    Programmed cell death (PCD) is a universal process in all multicellular organisms. It is a critical component in a diverse number of processes ranging from growth and differentiation to response to stress. Somatic embryogenesis is one such process where PCD is significantly involved. Nitric oxide is increasingly being recognized as playing a significant role in regulating PCD in both mammalian and plant systems. Plant hemoglobins scavenge NO, and evidence is accumulating that events that modify NO levels in plants also affect hemoglobin expression. Here, we review the process of PCD, describing the involvement of NO and plant hemoglobins in the process. NO is an effector of cell death in both plants and vertebrates, triggering the cascade of events leading to targeted cell death that is a part of an organism's response to stress or to tissue differentiation and development. Expression of specific hemoglobins can alter this response in plants by scavenging the NO, thus, interrupting the death process. Somatic embryogenesis is used as a model system to demonstrate how cell-specific expression of different classes of hemoglobins can alter the embryogenic process, affecting hormone synthesis, cell metabolite levels and genes associated with PCD and embryogenic competence. We propose that plant hemoglobins influence somatic embryogenesis and PCD through cell-specific expression of a distinct plant hemoglobin. It is based on the premise that both embryogenic competence and PCD are strongly influenced by cellular NO levels. Increases in cellular NO levels result in elevated Zn(2+) and reactive-oxygen species associated with PCD, but they also result in decreased expression of MYC2, a transcription factor that is a negative effector of indoleacetic acid synthesis, a hormone that positively influences embryogenic competence. Cell-specific hemoglobin expression reduces NO levels as a result of NO scavenging, resulting in cell survival.

  16. pH effects on the binding of oxygen to non-vertebrate monomeric hemoglobins. A linked function model.

    PubMed

    Saroff, Harry A

    2004-07-07

    Monomeric invertabrate hemoglobins with high oxygen affinity usually contain a tyrosine in the distal region of the heme. This feature has stimulated investigations revealing that one of the properties resulting from the presence of the distal tyrosines is a decreased off rate on the binding of oxygen, thus developing the high affinity. Despite that fact that the pK value of the tyrosine group differs significantly from the groups it replaces little attention has been paid to the pH dependence of the binding of oxygen to the high affinity hemoglobins. Such a pH dependence has been reported on two of the monomeric hemoglobins with relatively low oxygen affinity and one monomeric hemoglobin of intermediate affinity. The pH data of these hemoglobins has been analysed with a linked function model involving the hydrogen ion. pK values required for the low-affinity hemoglobins vary from 4.5 to 7.5. When applied to the high-affinity hemoglobins, the linked function model provides reasonable values for the binding parameters. These pK values vary from 3.0 to 9.0.

  17. The effect of exposure to nanoparticles and nanomaterials on the mammalian epigenome.

    PubMed

    Sierra, M I; Valdés, A; Fernández, A F; Torrecillas, R; Fraga, M F

    Human exposure to nanomaterials and nanoparticles is increasing rapidly, but their effects on human health are still largely unknown. Epigenetic modifications are attracting ever more interest as possible underlying molecular mechanisms of gene-environment interactions, highlighting them as potential molecular targets following exposure to nanomaterials and nanoparticles. Interestingly, recent research has identified changes in DNA methylation, histone post-translational modifications, and noncoding RNAs in mammalian cells exposed to nanomaterials and nanoparticles. However, the challenge for the future will be to determine the molecular pathways driving these epigenetic alterations, the possible functional consequences, and the potential effects on health.

  18. The effect of exposure to nanoparticles and nanomaterials on the mammalian epigenome

    PubMed Central

    Sierra, MI; Valdés, A; Fernández, AF; Torrecillas, R; Fraga, MF

    2016-01-01

    Human exposure to nanomaterials and nanoparticles is increasing rapidly, but their effects on human health are still largely unknown. Epigenetic modifications are attracting ever more interest as possible underlying molecular mechanisms of gene–environment interactions, highlighting them as potential molecular targets following exposure to nanomaterials and nanoparticles. Interestingly, recent research has identified changes in DNA methylation, histone post-translational modifications, and noncoding RNAs in mammalian cells exposed to nanomaterials and nanoparticles. However, the challenge for the future will be to determine the molecular pathways driving these epigenetic alterations, the possible functional consequences, and the potential effects on health. PMID:27932878

  19. Effects of Insecticidal Ketones Present in Mint Plants on GABAA Receptor from Mammalian Neurons

    PubMed Central

    Sánchez-Borzone, Mariela Eugenia; Marin, Leticia Delgado; García, Daniel Asmed

    2017-01-01

    Background: The genus Mentha, an important member of the Lamiaceae family, is represented by many species commonly known as mint. The insecticidal activity of Mentha oil and its main components has been tested and established against various insects/pests. Among these, the ketone monoterpenes that are most common in different Mentha species demonstrated insect toxicity, with pulegone being the most active, followed by carvone and menthone. Considering that the GABAA receptor (GABAA-R) is one of the main insecticide targets on neurons, and that pulegone would modulate the insect GABA system, it may be expected that the insecticidal properties of Mentha ketones are mediated by their interaction with this receptor. Objective: In order to discern the pharmacological actions of these products when used as insecticides on mammalian organisms, we evaluated the pharmacologic activity of ketones, commonly present in Mentha plants, on native GABAA-R from rats. Materials and Methods: Determination of ketones effects on allosterically enhanced benzodiazepine binding, using primary cultures of cortical neurons, which express functional receptors and MTT assay to evaluate their cell toxicity. Results: Our results seem to indicate that ketone components of Mentha, with proven repellent or insecticide activity, were able to behave as GABAA-R negative allosteric modulators in murine cells and consequently could exhibit convulsant activity in mammalians. Only pulegone at the highest assayed concentration (2 mM) showed a significant reduction in cell viability after exposure for 24 hr. Conclusion: The present results strongly suggest that the ketone components of Mentha are able to exhibit convulsant activity in mammalian organisms, but functional assays and in vivo experiments would be necessary to corroborate this proposed action. SUMMARY The pharmacological activity of insecticide ketones, commonly present in Mentha plants, was evaluated on native GABAA receptor from mammalian

  20. [Effectiveness of weekly iron supplementation on hemoglobin concentration, nutritional status and development of infants of public daycare centers in Recife, Pernambuco State, Brazil].

    PubMed

    Eickmann, Sophie H; Brito, Cristiana M M; Lira, Pedro I C; Lima, Marilia C

    2008-01-01

    This study analyzed the effectiveness of weekly iron supplementation on hemoglobin concentration, nutritional status, and mental and motor development of infants at four public daycare centers in Recife, Pernambuco State, Brazil. This was a before-after intervention study conducted with weekly iron supplementation for six months in a sample of 76 infants in the 4 to 24 month age group, from February to December 2005. Mental and motor development was assessed through the Bayley Scale of Infant Development II. After supplementation, a significant increase was observed in hemoglobin concentration in the group of infants with initial hemoglobin level < or = 9.5g/dL (p = 0.001). There was also a significant increase in the mean weight-for-length z-score, but the opposite was found for length-for-age. No difference was observed in the developmental indices. We conclude that weekly iron supplementation was effective for increasing hemoglobin concentration in infants with lower initial levels, but no impact on infant development was observed.

  1. The evolution of polar fish hemoglobin: a phylogenetic analysis of the ancestral amino acid residues linked to the root effect.

    PubMed

    Verde, Cinzia; Parisi, Elio; di Prisco, Guido

    2003-01-01

    Originating from a benthic ancestor, the suborder Notothenioidei (the dominant fish fauna component of the Antarctic sea) underwent a remarkable radiation, which led notothenioids to fill several niches. The ecological importance of notothenioids in Antarctica and their biochemical adaptations have prompted great efforts to study their physiology and phylogeny, with special attention to the evolutionary adaptation of the oxygen-transport system. We herewith report the evolutionary history of alpha- and beta-globins under the assumption of the molecular clock hypothesis as a basis for reconstructing the phylogenetic relationships among species. These studies have been extended to fish species of other latitudes, including the Arctic region. The northern and southern polar oceans have very different characteristics; indeed, in many respects the Antarctic and Arctic ichthyofaunas are more dissimilar than similar. Our results show that the inferred phylogeny of Arctic and Antarctic globins is different. Taking advantage of the wealth of information collected on structure and function of hemoglobins, we have attempted to investigate the evolutionary history of an important physiological feature in fish, the Root effect. The results suggest that the amino acid residues reported to play a key role in the Root effect may be regarded as ancestor characters, but the lack of this effect in extant species can hardly be associated with the presence of synapomorphies.

  2. Cytotoxic Effects of Tropodithietic Acid on Mammalian Clonal Cell Lines of Neuronal and Glial Origin

    PubMed Central

    Wichmann, Heidi; Vocke, Farina; Brinkhoff, Thorsten; Simon, Meinhard; Richter-Landsberg, Christiane

    2015-01-01

    The marine metabolite tropodithietic acid (TDA), produced by several Roseobacter clade bacteria, is known for its broad antimicrobial activity. TDA is of interest not only as a probiotic in aquaculture, but also because it might be of use as an antibacterial agent in non-marine or non-aquatic environments, and thus the potentially cytotoxic influences on eukaryotic cells need to be evaluated. The present study was undertaken to investigate its effects on cells of the mammalian nervous system, i.e., neuronal N2a cells and OLN-93 cells as model systems for nerve cells and glia. The data show that in both cell lines TDA exerted morphological changes and cytotoxic effects at a concentration of 0.3–0.5 µg/mL (1.4–2.4 µM). Furthermore, TDA caused a breakdown of the mitochondrial membrane potential, the activation of extracellular signal-regulated kinases ERK1/2, and the induction of the small heat shock protein HSP32/HO-1, which is considered as a sensor of oxidative stress. The cytotoxic effects were accompanied by an increase in intracellular Ca2+-levels, the disturbance of the microtubule network, and the reorganization of the microfilament system. Hence, mammalian cells are a sensitive target for the action of TDA and react by the activation of a stress response resulting in cell death. PMID:26633426

  3. The effects of ginger on fasting blood sugar, hemoglobin a1c, apolipoprotein B, apolipoprotein a-I and malondialdehyde in type 2 diabetic patients.

    PubMed

    Khandouzi, Nafiseh; Shidfar, Farzad; Rajab, Asadollah; Rahideh, Tayebeh; Hosseini, Payam; Mir Taheri, Mohsen

    2015-01-01

    Diabetes mellitus is the most common endocrine disorder, causes many complications such as micro- and macro-vascular diseases. Anti-diabetic, hypolipidemic and anti-oxidative properties of ginger have been noticed in several researches. The present study was conducted to investigate the effects of ginger on fasting blood sugar, Hemoglobin A1c, apolipoprotein B, apolipoprotein A-I, and malondialdehyde in type 2 diabetic patients. In a randomized, double-blind, placebo-controlled, clinical trial, a total of 41 type 2 diabetic patients randomly were assigned to ginger or placebo groups (22 in ginger group and 19 in control group), received 2 g/day of ginger powder supplement or lactose as placebo for 12 weeks. The serum concentrations of fasting blood sugar, Hemoglobin A1c, apolipoprotein B, apolipoprotein A-I and malondialdehyde were analyzed before and after the intervention. Ginger supplementation significantly reduced the levels of fasting blood sugar, hemoglobin A1c, apolipoprotein B, apolipoprotein B/apolipoprotein A-I and malondialdehyde in ginger group in comparison to baseline, as well as control group, while it increased the level of apolipoprotein A-I (p<0.05). It seems that oral administration of ginger powder supplement can improves fasting blood sugar, hemoglobin A1c, apolipoprotein B, apolipoprotein A-I, apolipoprotein B/apolipoprotein A-I and malondialdehyde in type 2 diabetic patients. So it may have a role in alleviating the risk of some chronic complications of diabetes.

  4. The effect of zinc and vitamin C supplementation on hemoglobin and hematocrit levels and immune response in patients with Plasmodium vivax malaria.

    PubMed

    Zen Rahfiludin, M; Ginandjar, Praba

    2013-09-01

    Plasmodium vivax infection in humans can relapse and is associated with iron deficiency. The immune response plays an important role in preventing relapse. In this study we analyzed the effect of zinc and vitamin C supplementation on hemoglobin and hematocrit levels and immune response in patients with P. vivax malaria. We measured immune response by examining interferon gamma (IFN-gamma) and interleukin-10 (IL-10) levels. Subjects were divided into either treatment or control groups. The treatment group received daily zinc and vitamin C supplementation for 45 days. Compliance with supplement consumption was recorded weekly. After 45 days of supplementation, IFN-gamma and IL-1 levels were remeasured. All study subjects in both groups had normal hemoglobin and hematocrit levels. The hemoglobin levels increased only in the supplementation group (p=0.011), while hematocrit levels increased in both the supplementation (p=0.001) and control (p=0.023) groups. IFN-gamma decreased slightly in the supplementation group, but the change was not significant (p=0.688). IL-10 increased slightly in both the supplementation and the control groups, but the change were not significant (p=0.421 and p=0.556, respectively), suggesting the elevated hemoglobin and hematocrit levels were unrelated to immune response.

  5. Long-Term Stored Hemoglobin-Vesicles, a Cellular Type of Hemoglobin-Based Oxygen Carrier, Has Resuscitative Effects Comparable to That for Fresh Red Blood Cells in a Rat Model with Massive Hemorrhage without Post-Transfusion Lung Injury

    PubMed Central

    Yamasaki, Keishi; Sakai, Hiromi; Otagiri, Masaki

    2016-01-01

    Hemoglobin-vesicles (HbV), encapsulating highly concentrated human hemoglobin in liposomes, were developed as a substitute for red blood cells (RBC) and their safety and efficacy in transfusion therapy has been confirmed in previous studies. Although HbV suspensions are structurally and physicochemically stabile for least 1-year at room temperature, based on in vitro experiments, the issue of whether the use of long-term stored HbV after a massive hemorrhage can be effective in resuscitations without adverse, post-transfusion effects remains to be clarified. We report herein on a comparison of the systemic response and the induction of organ injuries in hemorrhagic shock model rats resuscitated using 1-year-stored HbV, freshly packed RBC (PRBC-0) and by 28-day-stored packed RBC (PRBC-28). The six-hour mortality after resuscitation was not significantly different among the groups. Arterial blood pressure and blood gas parameters revealed that, using HbV, recovery from the shock state was comparable to that when PRBC-0 was used. Although no significant change was observed in serum parameters reflecting liver and kidney injuries at 6 hours after resuscitation among the three resuscitation groups, results based on Evans Blue and protein leakage in bronchoalveolar lavage fluid, the lung wet/dry weight ratio and histopathological findings indicated that HbV as well as PRBC-0 was less predisposed to result in a post-transfusion lung injury than PRBC-28, as evidenced by low levels of myeloperoxidase accumulation and subsequent oxidative damage in the lung. The findings reported herein indicate that 1-year-stored HbV can effectively function as a resuscitative fluid without the induction of post-transfused lung injury and that it is comparable to fresh PRBC, suggesting that HbV is a promising RBC substitute with a long shelf-life. PMID:27798697

  6. Effects of pressure on visible spectra of complexes of myoglobin, hemoglobin, cytochrome c, and horse radish peroxidase.

    PubMed

    Ogunmola, G B; Zipp, A; Chen, F; Kauzmann, W

    1977-01-01

    The spectra of the ferric form of most heme proteins [metmyoglobin, methemoglobin, horse radish peroxidase (EC 1.11.1.7), and ferricytochrome c at pH 1.5] are converted from high-spin (open crevice) structure to low-spin (closed crevice) form under pressure. Pressures up to 8000 kg/cm2 (780 MPa) have no effect on the spectra of high-spin ferro- and ferricytochrome c, which have a closed crevice structure at pH 7.0. Spectra of deoxy-ferromyoglobin and deoxy-ferrohemoglobin are reduced in intensity, but pressure does not change the positions of the absorption maxima. Cyanide ion prevents pressure-induced spectral changes in metmyoglobin and methemoglobin up to 8000 kg/cm2. Carbon monoxide (with a high affinity for the ferro heme iron) has a similar effect on ferromyoglobin and ferrohemoglobin. The pressure required to cause spectral changes in the heme proteins falls in the order, cytochrome c (pH 7.0) greater than horse radish peroxidase greater than myoglobin greater than hemoglobin. We have calculated a volume change of --50 cm3/mol associated with the configurational change accompanying the reformation of the iron-methionine bond in cytochrome c at low pH.

  7. Effects of carbon source and Vitreoscilla hemoglobin (VHb) on the production of beta-galactosidase in Enterobacter aerogenes.

    PubMed

    Khleifat, Khaled M; Abboud, Muayad M; Al-Mustafa, Ahmed H; Al-Sharafa, Khalid Y

    2006-10-01

    At fixed concentration (0.5%), lactose and galactose acted as inducers while glucose and other tested carbon sugars showed repression effects on beta-galactosidase production in Enterobacter aerogenes strain. The expression of Vitreoscilla hemoglobin gene (vgb) in this bacterial strain managed to overcome the repression effects as well as improving the induction of beta-galactosidase formation by carbon sources. In parallel, the bacterial O(2) consumption was increased correspondingly to the vgb induction of beta-galactosidase synthesis. When Enterobacter aerogenes strains were grown at the incubation temperature 42 degrees C, about 5-fold higher enzyme productivity was obtained than with a similar incubation at 37 degrees C. The bacterial growth expressed as biomass yield had a different optimum temperature and was not influenced to the same extent by variations in the carbon sources. These data are discussed in terms of proposed enhancement in beta-galactosidase productivity by vgb expression as well as its significance to improve the technology of whey processing.

  8. An insect-tapeworm model as a proxy for anthelminthic effects in the mammalian host.

    PubMed

    Woolsey, Ian David; Fredensborg, Brian L; Jensen, Per M; Kapel, Christian M O; Meyling, Nicolai V

    2015-07-01

    Invertebrate models provide several important advantages over their vertebrate counterparts including fewer legislative stipulations and faster, more cost-effective experimental procedures. Furthermore, various similarities between insect and mammalian systems have been highlighted. To obtain maximum use of invertebrate models in pharmacology, their fidelity as analogues of vertebrate systems requires verification. We utilised a flour beetle (Tenebrio molitor)-tapeworm (Hymenolepis diminuta) model to evaluate the efficacy of known anthelmintic compounds, praziquantel, mebendazole and levamisole against H. diminuta cysticercoid larvae in vitro. Inhibition of cysticercoid activity during the excystation procedure was used as a proxy for worm removal. The effects of the three compounds mirrored their relative efficacy in treatment against adult worms in mammalian systems; however, further study is required to determine the fidelity of this model in relation to dose administered. The model precludes comparison of consecutive daily administration of pharmaceuticals in mammals due to cysticercoids not surviving outside of the host for multiple days. Treatment of beetles in vivo, followed by excystation of cysticercoids postdissection could potentially allow for such comparisons. Further model validation will include analysis of pharmaceutical efficacy in varying H. diminuta isolates and pharmaceutical dilution in solvents other than water. Notwithstanding, our results demonstrate that this model holds promise as a method to efficiently identify promising new cestocidal candidates.

  9. Hepatoprotective effects of Poly-[hemoglobin-superoxide dismutase-catalase-carbonic anhydrase] on alcohol-damaged primary rat hepatocyte culture in vitro.

    PubMed

    Jiang, Wenhua; Bian, Yuzhu; Wang, Zhenghui; Chang, Thomas Ming Swi

    2017-02-01

    We have prepared a novel nanobiotherapeutic, Poly-[hemoglobin-superoxide dismutase-catalase-carbonic anhydrase], which not only transports both oxygen and carbon dioxide but also a therapeutic antioxidant. Our previous study in a severe sustained 90 min hemorrhagic shock rat model shows that it has a hepatoprotective effect. We investigate its hepatoprotective effect further in this present report using an alcohol-damaged primary hepatocyte culture model. Results show that it significantly reduced ethanol-induced AST release, lipid peroxidation, and ROS production in rat primary hepatocytes culture. It also significantly enhanced the viability of ethanol-treated hepatocytes. Thus, the result shows that Poly-[hemoglobin-superoxide dismutase-catalase-carbonic anhydrase] also has some hepatoprotective effects against alcohol-induced injury in in vitro rat primary hepatocytes cell culture. This collaborate our previous observation of its hepatoprotective effect in a severe sustained 90-min hemorrhagic shock rat model.

  10. The Effects of Dietary Iron and Capsaicin on Hemoglobin, Blood Glucose, Insulin Tolerance, Cholesterol, and Triglycerides, in Healthy and Diabetic Wistar Rats

    PubMed Central

    Villalpando-Hernández, Salvador; Ríos-Silva, Mónica; Díaz-Reval, María I.; Cruzblanca, Humberto; Mancilla, Evelyn

    2016-01-01

    Objective Our aim was to assess the effects of dietary iron, and the compound capsaicin, on hemoglobin as well as metabolic indicators including blood glucose, cholesterol, triglycerides, insulin, and glucose tolerance. Materials and Methods Our animal model was the Wistar rat, fed a chow diet, with or without experimentally induced diabetes. Diabetic males were fed control, low, or high-iron diets, the latter, with or without capsaicin. Healthy rats were fed identical diets, but without the capsaicin supplement. We then measured the parameters listed above, using the Student t-test and ANOVA, to compare groups. Results Healthy rats fed a low-iron diet exhibited significantly reduced total cholesterol and triglyceride levels, compared with rats fed a control diet. Significantly reduced blood lipid was also provoked by low dietary iron in diabetic rats, compared with those fed a control diet. Insulin, and glucose tolerance was only improved in healthy rats fed the low-iron diet. Significant increases in total cholesterol were found in diabetic rats fed a high-iron diet, compared with healthy rats fed the same diet, although no statistical differences were found for triglycerides. Hemoglobin levels, which were not statistically different in diabetic versus healthy rats fed the high-iron diet, fell when capsaicin was added. Capsaicin also provoked a fall in the level of cholesterol and triglycerides in diabetic animals, versus diabetics fed with the high iron diet alone. In conclusion, low levels of dietary iron reduced levels of serum triglycerides, hemoglobin, and cholesterol, and significantly improved insulin, and glucose tolerance in healthy rats. In contrast, a high-iron diet increased cholesterol significantly, with no significant changes to triglyceride concentrations. The addition of capsaicin to the high-iron diet (for diabetic rats) further reduced levels of hemoglobin, cholesterol, and triglycerides. These results suggest that capsaicin, may be suitable

  11. Primary structure and functional properties of the hemoglobin from the free-tailed bat Tadarida brasiliensis (Chiroptera). Small effect of carbon dioxide on oxygen affinity.

    PubMed

    Kleinschmidt, T; Rücknagel, K P; Weber, R E; Koop, B F; Braunitzer, G

    1987-06-01

    The hemoglobin of the Free-Tailed Bat Tadarida brasiliensis (Microchiroptera) comprises two components (Hb I and Hb II) in nearly equal amounts. Both hemoglobins have identical beta-chains, whereas the alpha-chains differ in having glycine (Hb I) or aspartic acid (Hb II) in position 115 (GH3). The components could be isolated by DEAE-Sephacel chromatography and separated into the globin chains by chromatography on carboxymethyl-cellulose CM-52. The sequences have been determined by Edman degradation with the film technique or the gas phase method (the alpha I-chains with the latter method only), using the native chains and tryptic peptides, as well as the C-terminal prolyl-peptide obtained by acid hydrolysis of the Asp-Pro bond in the beta-chains. The comparison with human hemoglobin showed 18 substitutions in the alpha-chains and 24 in the beta-chains. In the alpha-chains one amino-acid exchange involves an alpha 1/beta 1-contact. In the beta-chains one heme contact, three alpha 1/beta 1- and one alpha 1/beta 2-contacts are substituted. A comparison with other chiropteran hemoglobin sequences shows similar distances to Micro- and Megachiroptera. The oxygenation characteristics of the composite hemolysate and the two components, measured in relation to pH, Cl-, and 2,3-bis-phosphoglycerate, are described. The effect of carbon dioxide on oxygen affinity is considerably smaller than that observed in human hemoglobin, which might be an adaptation to life under hypercapnic conditions.

  12. The effects of selenium on glutathione peroxidase activity and radioprotection in mammalian cells

    SciTech Connect

    Diamond, A.M.; Murray, J.L.; Dale, P.; Tritz, R.; Grdina, D.J.

    1995-09-05

    The media of representative mammalian cell lines were supplemented with low levels of selenium in the form of sodium selenite in order to investigate the effects of selenium on mammalian cells. Following incubation in 30 nM sodium selenite, these cells were assayed for changes in glutathione peroxidase (GPx) activity. The cells examined included NIH 3T3 mouse fibroblasts, PC12 rat sympathetic precursor cells, SupT-1 human lymphocytes, MCF-7{sup adr} human breast carcinoma cells and AA8 Chinese hamster ovary cells. Selenium supplementation resulted in a marginal increase in GPx activity for the NIH 3T3, MCF-7{sup adr} and Supt-1 cells but stimulated GPx activity approximately 5-fold in PC12 and AA8 cells. AA8 cells were selected to evaluate whether selenium supplementation was radioprotective against {sup 60}cobalt gamma irradiation. Protection against radiation-induced mutation was measured by evaluating mutation frequency at the hprt locus. In this assay, preincubation of AA8 CHO cells significantly protected these cells from exposure to 8 Gy.

  13. Immunomodulatory and radioprotective effects of lignans derived from fresh nutmeg mace (Myristica fragrans) in mammalian splenocytes.

    PubMed

    Checker, Rahul; Chatterjee, Suchandra; Sharma, Deepak; Gupta, Sumit; Variyar, Prasad; Sharma, Arun; Poduval, T B

    2008-05-01

    Recently, the lignans present in the aqueous extract of fresh nutmeg mace (aril of the fruit of Myristica fragrans) were shown to possess antioxidant properties in cell free systems and protected PUC18 plasmid against radiation-induced DNA damage. The present report describes the immunomodulatory and radiomodifying properties of lignans present in the aqueous extract of fresh nutmeg mace in mammalian splenocytes. These macelignans (ML) inhibited the proliferation of splenocytes in response to polyclonal T cell mitogen concanavalin A (Con A). This inhibition of proliferation was due to cell cycle arrest in G1 phase and augmentation of apoptosis as shown by increase in pre G1 cells. The increase in activation induced cell death by ML was dose dependent. It was found to inhibit the transcription of IL-2 and IL-4 genes in response to Con A. The production of IL-2, IL-4 and IFN-gamma cytokines was significantly inhibited by ML in Con A-stimulated lymphocytes in a dose dependent manner. ML protected splenocytes against radiation-induced intracellular ROS production in a dose dependent manner. ML was not cytotoxic towards lymphocytes. On the contrary, it significantly inhibited the radiation-induced DNA damage in splenocytes as indicated by decrease in DNA fragmentation. To our knowledge, this is the first report showing the antioxidant, radioprotective and immunomodulatory effects of lignans in mammalian cells.

  14. Anti-tumor effects of dehydroaltenusin, a specific inhibitor of mammalian DNA polymerase {alpha}

    SciTech Connect

    Maeda, Naoki; Kokai, Yasuo; Ohtani, Seiji; Sahara, Hiroeki; Kuriyama, Isoko; Kamisuki, Shinji; Takahashi, Shunya; Sakaguchi, Kengo; Sugawara, Fumio; Yoshida, Hiromi; Sato, Noriyuki; Mizushina, Yoshiyuki . E-mail: mizushin@nutr.kobegakuin.ac.jp

    2007-01-12

    In the screening of selective inhibitors of eukaryotic DNA polymerases (pols), dehydroaltenusin was found to be an inhibitor of pol {alpha} from a fungus (Alternaria tennuis). We succeeded in chemically synthesizing dehydroaltenusin, and the compound inhibited only mammalian pol {alpha} with IC{sub 50} value of 0.5 {mu}M, and did not influence the activities of other replicative pols such as pols {delta} and {epsilon}, but also showed no effect on pol {alpha} activity from another vertebrate, fish, or from a plant species. Dehydroaltenusin also had no influence on the other pols and DNA metabolic enzymes tested. The compound also inhibited the proliferation of human cancer cells with LD{sub 50} values of 38.0-44.4 {mu}M. In an in vivo anti-tumor assay on nude mice bearing solid tumors of HeLa cells, dehydroaltenusin was shown to be a promising suppressor of solid tumors. Histopathological examination revealed that increased tumor necrosis and decreased mitotic index were apparently detected by the compound in vivo. Therefore, dehydroaltenusin could be of interest as not only a mammalian pol {alpha}-specific inhibitor, but also as a candidate drug for anti-cancer treatment.

  15. Effects of mobile phone radiofrequency on the structure and function of the normal human hemoglobin.

    PubMed

    Mousavy, Seyed Jafar; Riazi, Gholam Hossein; Kamarei, Mahmood; Aliakbarian, Hadi; Sattarahmady, Naghmeh; Sharifizadeh, Ahmad; Safarian, Shahrokh; Ahmad, Faizan; Moosavi-Movahedi, Ali Akbar

    2009-04-01

    Widespread use of mobile phones has increased the human exposure to electromagnetic fields (EMFs). It is required to investigate the effect of EMFs on the biological systems. In this paper the effect of mobile phone RF (910MHz and 940 MHz) on structure and function of HbA was investigated. Oxygen affinity was measured by sodium dithionite with UV-vis spectrophotometer. Structural changes were studied by circular dichroism and fluorescence spectroscopy. The results indicated that mobile phone EMFs altered oxygen affinity and tertiary structure of HbA. Furthermore, the decrease of oxygen affinity of HbA corresponded to the EMFs intensity and time of exposure.

  16. Effect of low glycemic load diet on glycated hemoglobin (HbA1c) in poorly-controlled diabetes patients.

    PubMed

    Ziaee, Amir; Afaghi, Ahmad; Sarreshtehdari, Majied

    2011-12-29

    Different carbohydrate diets have been administrated to diabetic patients to evaluate the glycemic response, while Poor-controlled diabetes is increasing world wide. To investigate the role of an alternative carbohydrate diet on glycemic control, we explored the effect of a low glycemic load (Low GL)-high fat diet on glycemic response and also glycated hemoglobin (HbA1c) of poor-controlled diabetes patients. Hundred poorly-controlled diabetes patients, HbA1c > 8, age 52.8 ± 4.5 y, were administrated a low GL diet , GL = 67 (Energy 1800 kcal; total fat 36%; fat derived from olive oil and nuts 15%; carbohydrate 42%; protein 22%) for 10 weeks. Patients did their routine life style program during intervention. Fasting blood glucose and HbA1c before and after intervention with significant reduction were: 169 ± 17, 141 ± 12; 8.85% (73 mmol/mol) ± 0.22%, and 7.81% (62 mmol/mol) ± 0.27%; respectively (P < 0.001). Mean fasting blood glucose reduced by 28.1 ± 12.5 and HbA1c by 1.1% (11 mmol/mol) ± 0.3% (P=0.001). There was positive moderate correlation between HbA1c concentration before intervention and FBS reduction after intervention (P < 0.001, at 0.01 level, R =0.52), and strong positive correlation between FBS before intervention and FBS reduction (P < 0.001, at 0.01 level, R = 0.70). This study demonstrated that our alternative low glycemic load diet can be effective in glycemic control.

  17. Effects of egg and vitamin A supplementation on hemoglobin, retinol status and physical growth levels of primary and middle school students in Chongqing, China.

    PubMed

    Cao, Jiaoyang; Wei, Xiaoping; Tang, Xianqiang; Jiang, Hongpeng; Fan, Zhen; Yu, Qin; Chen, Jie; Liu, Youxue; Li, Tingyu

    2013-01-01

    Lack of protein and vitamin A influences the growth of student in impoverished mountain areas. The aim of the study was to assess the effects of egg and vitamin A supplementation on hemoglobin, serum retinol and anthropometric indices of 10-18 years old students of a low socioeconomic status. A total number of 288 students from four boarding schools were randomly selected by using cluster sampling method in Chongqing, and they were assigned into supplement group and control group non-randomly. Students in supplement group received a single 200,000 international units vitamin A and 1 egg/day (including weekends) for 6 months. The control group did not receive any supplementation. We measured hemoglobin, serum retinol and height and weight at baseline and after supplementation. The supplementation increased the mean hemoglobin concentration by 7.13 g/L compared with 1.38 g/L in control group (p<0.001), the mean serum retinol concentration by 0.31 μmol/L compared with 0.09 μmol/L in the control group (p=0.005), the mean height-for-age z score by 0.05 compared with 0.03 in the control group (p=0.319), the mean weight-for-age z score by 0.05 compared with -0.12 in the control group (p<0.001). Our results revealed that egg and vitamin A supplementation is an effective, convenient, and practical method to improve the levels of hemoglobin, serum retinol and prevent the deterioration of growth in terms of weight for primary and middle school students from outlying poverty-stricken areas. Our intervention did not have a beneficial effect on linear growth.

  18. Is hemoglobin A1c level effective in predicting the prognosis of Fournier gangrene?

    PubMed Central

    Sen, Haluk; Bayrak, Omer; Erturhan, Sakip; Borazan, Ersin; Koc, Mustafa Nihat

    2016-01-01

    Objectives: To evaluate the effect of immune failure and/or diabetes mellitus (DM) association on the mortality and morbidity of the Fournier's Gangrene (FG), and interrelatedly, the usability of HbA1c level in the prediction of prognosis. Materials and Methods: The data of 38 patients with the diagnosis of FG were investigated retrospectively. The patients were divided into two groups as patients with DM (Group 1, n = 18) and non-diabetics (Group 2, n = 20). The patients in group 1 were also divided into two subgroups as patients with HbA1c value ≥7 (Group 1a) and HbA1c value <7 (Group 1b). Results: The mean age of all 38 male patients was 66.3 ± 6.4 years. The initial symptoms were scrotal rash and swelling (n = 20, 52.6%), high fever (>38°C) (n = 22, 57.8%), purulent discharge from genital or perineal areas (n = 13, 34.2%), skin bruises (n = 11, 28.9%) and general state disorder in five patients that were admitted from day care center (13.1%). DM, as the most often comorbid disease, was detected in 18 patients (47.3%). Six patients (15.7%) were deceased during the follow-up period. Conclusion: In the present study, the researchers determined that diabetic patients with HbA1c level of 7 or higher had worse prognosis, and increased mortality. PMID:27453658

  19. O2-Filled Swimbladder Employs Monocarboxylate Transporters for the Generation of O2 by Lactate-Induced Root Effect Hemoglobin

    PubMed Central

    Umezawa, Takahiro; Kato, Akira; Ogoshi, Maho; Ookata, Kayoko; Munakata, Keijiro; Yamamoto, Yoko; Islam, Zinia; Doi, Hiroyuki; Romero, Michael F.; Hirose, Shigehisa

    2012-01-01

    The swimbladder volume is regulated by O2 transfer between the luminal space and the blood In the swimbladder, lactic acid generation by anaerobic glycolysis in the gas gland epithelial cells and its recycling through the rete mirabile bundles of countercurrent capillaries are essential for local blood acidification and oxygen liberation from hemoglobin by the “Root effect.” While O2 generation is critical for fish flotation, the molecular mechanism of the secretion and recycling of lactic acid in this critical process is not clear. To clarify molecules that are involved in the blood acidification and visualize the route of lactic acid movement, we analyzed the expression of 17 members of the H+/monocarboxylate transporter (MCT) family in the fugu genome and found that only MCT1b and MCT4b are highly expressed in the fugu swimbladder. Electrophysiological analyses demonstrated that MCT1b is a high-affinity lactate transporter whereas MCT4b is a low-affinity/high-conductance lactate transporter. Immunohistochemistry demonstrated that (i) MCT4b expresses in gas gland cells together with the glycolytic enzyme GAPDH at high level and mediate lactic acid secretion by gas gland cells, and (ii) MCT1b expresses in arterial, but not venous, capillary endothelial cells in rete mirabile and mediates recycling of lactic acid in the rete mirabile by solute-specific transcellular transport. These results clarified the mechanism of the blood acidification in the swimbladder by spatially organized two lactic acid transporters MCT4b and MCT1b. PMID:22496829

  20. Single breath diffusing capacity for carbon monoxide: effects of adjustment for inspired volume dead space, carbon dioxide, hemoglobin and carboxyhemoglobin.

    PubMed

    Viegi, G; Baldi, S; Begliomini, E; Ferdeghini, E M; Pistelli, F

    1998-01-01

    In order to assess the additive effects of taking into account dead space volume (VD), carbon dioxide, hemoglobin (Hb) and carboxyhemoglobin on computation of single breath carbon monoxide diffusing capacity (DLCOsb), we sequentially applied all the corrections recommended by the 1987 American Thoracic Society (ATS) document on DLCOsb standardization. We used data from 739 men (333 nonsmokers and 406 current smokers) and 475 women (403 nonsmokers and 72 current smokers) who underwent measurement of DLCOsb in the decade 1985-1994 at the Lung Function Laboratory of our institute. With respect to the unadjusted DLCOsb value, significant small differences were found for all the corrected formulas, ranging from -0.18 to 1.48 ml/min/mm Hg in men and from -0.24 to 1.57 ml/min/mm Hg in women. After computing the percent change of DLCOsb [(unadjusted-adjusted value) x 100/unadjusted value], we observed that the correction for VD caused an underestimation of DLCOsb of about 5.8% in men and 7.7% in women. However, when all the corrections were considered, these figures decreased to about 0.9% in males and 2.9% in females. Regarding specifically the correction for Hb, the adjusted value was slightly lower in men, while it was some-what higher in women, with respect to the unadjusted DLCOsb. In conclusion, the corrections suggested by ATS in the computation of DLCOsb, when considered altogether, seem to account for a limited proportion of test variability in usual clinical conditions, especially in males.

  1. Effect of biosynthetic manipulation of heme on insolubility of Vitreoscilla hemoglobin in Escherichia coli

    SciTech Connect

    Hart, R.A.; Kallio, P.T.; Bailey, J.E.

    1994-07-01

    Vitreoscilla hemoglobulin (VHb) is accumulated at high levels in both soluble and insoluble forms when expressed from its native promoter on a pUC19-derived plasmid in Escherichia coli. Examination by atomic absorption spectroscopy and electron paramagnetic resonance spectroscopy revealed that the insoluble form uniformly lacks the heme prosthetic group (apoVHb). The purified soluble form contains heme (holoVHb) and is spectroscopically indistinguishable from holoVHb produced by Vitreoscilla cells. This observation suggested that a relationship may exist between the insolubility of apoVHb and biosynthesis of heme. To examine this possibility, a series of experiments were conducted to chemically and genetically manipulate the formation and conversion of 5-aminolevulinic acid (ALA), a key intermediate in heme biosynthesis. Chemical perturbations involved supplementing the growth medium with the intermediate ALA and the competitive inhibitor levulinic acid which freely cross the cell barrier. Genetic manipulations involved amplifying the gene dosage for the enzymes ALA synthase and ALA dehydratase. Results from both levulinic acid and ALA supplementations indicate that the level of soluble holoVHb correlates with the heme level but that the level of insoluble apoVHb does not. The ratio of soluble to insoluble VHb also does not correlate with the level of total VHb accumulated. The effect of amplifying ALA synthase and ALA dehydratase gene dosage is complex and may involve secondary factors. Results indicate that the rate-limiting step of heme biosynthesis in cells overproducing VHb does not lie at ALA synthesis, as it reportedly does in wild-type E. coli. 26 refs., 6 figs., 1 tab.

  2. Extrapulmonary effects of inhaled nitric oxide: role of reversible S-nitrosylation of erythrocytic hemoglobin.

    PubMed

    McMahon, Timothy J; Doctor, Allan

    2006-04-01

    Early applications of inhaled nitric oxide (iNO), typically in the treatment of diseases marked by acute pulmonary hypertension, were met by great enthusiasm regarding the purported specificity of iNO: vasodilation by iNO was specific to the lung (without a change in systemic vascular resistance), and within the lung, NO activity was said to be confined spatially and temporally by Hb within the vascular lumen. Underlying these claims were classical views of NO as a short-lived paracrine hormone that acts largely through the heme groups of soluble guanylate cyclase, and whose potential activity is terminated on encountering the hemes of red blood cell (RBC) Hb. These classical views are yielding to a broader paradigm, in which NO-related signaling is achieved through redox-related NO adducts that endow NO synthase products with the ability to act at a distance in space and time from NO synthase itself. Evidence supporting the biological importance of such stable NO adducts is probably strongest for S-nitrosothiols (SNOs), in which NO binds to critical cysteine residues in proteins or peptides. The circulating RBC is a major SNO reservoir, and RBC Hb releases SNO-related bioactivity peripherally on O2 desaturation. These new paradigms describing NO transport also provide a plausible mechanistic understanding of the increasingly recognized peripheral effects of inhaled NO. An explanation for the peripheral actions of inhaled NO is discussed here, and the rationale and results of attempts to exploit the "NO delivery" function of the RBC are reviewed.

  3. Effect of recombinant human growth hormone (rhGH) on hemoglobin concentration in children with idiopathic growth hormone deficiency-related anemia.

    PubMed

    Miniero, Roberto; Altomare, Federica; Rubino, Mario; Matarazzo, Patrizia; Montanari, Claudio; Petri, Antonella; Raiola, Giuseppe; Bona, Gianni

    2012-08-01

    Normocytic-normochromic anemia (NC/NC) has been attributed to impaired bone marrow erythropoiesis in growth hormone (GH)-deficient patients. Moreover, the GH/insulin-like growth factor-1 (IGF-1) axis has been implicated in erythropoiesis regulation. In this retrospective multicenter study, we evaluated the incidence of NC/NC anemia in 279 children (196 boys), median age 10.52 years, with isolated idiopathic GH deficiency, and the effect of recombinant human growth hormone (rhGH) therapy on hemoglobin levels. At 6-month intervals, we recorded the Hb standard deviation score (Hb-SDS), the IGF-1-SDS, weight, height, and pubertal stage. Forty-one boys and 7 girls had NC/NC anemia before starting substitutive therapy (-2.59 SD). The Hb-SDS was significantly increased (P<0.05) after 12 months of rhGH therapy. The effect of rhGH continued up to 48 months (-0.39 SD), at which point all children had normal hemoglobin values. In conclusion, rhGH therapy resulted in normal hemoglobin values in all children enrolled in the study. These data support the concept that the GH/IGF-1 axis promotes erythropoiesis in vivo.

  4. Phylogeny of Echinoderm Hemoglobins

    PubMed Central

    Christensen, Ana B.; Herman, Joseph L.; Elphick, Maurice R.; Kober, Kord M.; Janies, Daniel; Linchangco, Gregorio; Semmens, Dean C.; Bailly, Xavier; Vinogradov, Serge N.; Hoogewijs, David

    2015-01-01

    Background Recent genomic information has revealed that neuroglobin and cytoglobin are the two principal lineages of vertebrate hemoglobins, with the latter encompassing the familiar myoglobin and α-globin/β-globin tetramer hemoglobin, and several minor groups. In contrast, very little is known about hemoglobins in echinoderms, a phylum of exclusively marine organisms closely related to vertebrates, beyond the presence of coelomic hemoglobins in sea cucumbers and brittle stars. We identified about 50 hemoglobins in sea urchin, starfish and sea cucumber genomes and transcriptomes, and used Bayesian inference to carry out a molecular phylogenetic analysis of their relationship to vertebrate sequences, specifically, to assess the hypothesis that the neuroglobin and cytoglobin lineages are also present in echinoderms. Results The genome of the sea urchin Strongylocentrotus purpuratus encodes several hemoglobins, including a unique chimeric 14-domain globin, 2 androglobin isoforms and a unique single androglobin domain protein. Other strongylocentrotid genomes appear to have similar repertoires of globin genes. We carried out molecular phylogenetic analyses of 52 hemoglobins identified in sea urchin, brittle star and sea cucumber genomes and transcriptomes, using different multiple sequence alignment methods coupled with Bayesian and maximum likelihood approaches. The results demonstrate that there are two major globin lineages in echinoderms, which are related to the vertebrate neuroglobin and cytoglobin lineages. Furthermore, the brittle star and sea cucumber coelomic hemoglobins appear to have evolved independently from the cytoglobin lineage, similar to the evolution of erythroid oxygen binding globins in cyclostomes and vertebrates. Conclusion The presence of echinoderm globins related to the vertebrate neuroglobin and cytoglobin lineages suggests that the split between neuroglobins and cytoglobins occurred in the deuterostome ancestor shared by echinoderms and

  5. Hemoglobin-Based Nanoarchitectonic Assemblies as Oxygen Carriers.

    PubMed

    Jia, Yi; Duan, Li; Li, Junbai

    2016-02-10

    Safe and effective artificial oxygen carriers are the subject of great interest due to the problems of traditional blood transfusion and enormous demand in clinical use. In view of its unique oxygen-transport ability and normal metabolic pathways, hemoglobin is regarded as an ideal oxygen-carrying unit. With advances in nano-biotechnology, hemoglobin assemblies as artificial oxygen carriers achieve great development. Here, recent progress on hemoglobin-based oxygen carriers is highlighted in view of two aspects: acellular hemoglobin-based oxygen carriers and cellular hemoglobin-based oxygen carriers. These novel oxygen carriers exhibit advantages over traditional carriers and will greatly promote research on reliable and feasible oxygen carriers.

  6. Effects of Diaspirin Crosslinked Hemoglobin (DCLHb) on microcirculation and local tissue pO2 of striated skin muscle following resuscitation from hemorrhagic shock.

    PubMed

    Hungerer, Sven; Nolte, Dirk; Botzlar, Andreas; Messmer, Konrad

    2006-01-01

    The hemoglobin based oxygen carrier (HBOC) Diaspirin Crosslinked Hemoglobin (DCLHb) has been developed to substitute not only the blood volume, but also to restore the oxygen-carrying properties of blood during hemorrhagic shock. However, it has been suggested that HBOCs may enhance the formation of free oxygen radicals through the release of free iron ions via the Haber-Weiss reaction. The aim of this study was to investigate the effects of DCLHb on the microcirculation, leukocyte-endothelial cell interaction and local tissue oxygenation in striated skin muscle of Syrian golden hamsters during and after resuscitation from hemorrhagic shock. In particular we focused on the local tissue oxygenation after resuscitation with DCLHb (hemoglobin content 10 g%) compared to resuscitation using autologous blood diluted to a hemoglobin content of 10 g%. Hemorrhagic shock was induced for 45 minutes by bleeding the animals at a rate of 33 ml/kg BW maintaining a mean arterial pressure of 30 +/- 5 mmHg. Animals were resuscitated either with 33 ml/kg BW 6% Dextran-60.000 or with 10 g% DCLHb. The control group received shed blood diluted with Ringers to a hemoglobin content of 10 g%. Intravital microscopy was used for investigation of the microcirculatory parameters and a multiwire platinum surface electrode for measurement of local tissue pO2 in striated skin muscle in the dorsal skinfold chamber of Syrian golden hamsters. Resuscitation from hemorrhagic shock with 10 g% AUB revealed significant increase of leukocytes rolling in postcapillary venules at 30 to 120 minutes after resuscitation compared to baseline values. DCLHb turned out to reduce the number of firmly adherent leukocytes after resuscitation compared to 10 g% AUB. Microvascular permeability as an indicator for functional endothelial integrity revealed no significant differences between the groups. DCLHb and 10 g% AUB led to a significant increase in local tissue oxygenation after resuscitation from hemorrhagic shock

  7. Syntheses of nicotinamide riboside and derivatives: effective agents for increasing nicotinamide adenine dinucleotide concentrations in mammalian cells.

    PubMed

    Yang, Tianle; Chan, Noel Yan-Ki; Sauve, Anthony A

    2007-12-27

    A new two-step methodology achieves stereoselective synthesis of beta-nicotinamide riboside and a series of related amide, ester, and acid nucleosides. Compounds were prepared through a triacetylated-nicotinate ester nucleoside, via coupling of either ethylnicotinate or phenylnicotinate with 1,2,3,5-tetra-O-acetyl-beta-D-ribofuranose. Nicotinamide riboside, nicotinic acid riboside, O-ethylnicotinate riboside, O-methylnicotinate riboside, and several N-alkyl derivatives increased NAD+ concentrations from 1.2-2.7-fold in several mammalian cell lines. These findings establish bioavailability and potent effects of these nucleosides in stimulating the increase of NAD+ concentrations in mammalian cells.

  8. Mammalian sleep

    NASA Astrophysics Data System (ADS)

    Staunton, Hugh

    2005-05-01

    This review examines the biological background to the development of ideas on rapid eye movement sleep (REM sleep), so-called paradoxical sleep (PS), and its relation to dreaming. Aspects of the phenomenon which are discussed include physiological changes and their anatomical location, the effects of total and selective sleep deprivation in the human and animal, and REM sleep behavior disorder, the latter with its clinical manifestations in the human. Although dreaming also occurs in other sleep phases (non-REM or NREM sleep), in the human, there is a contingent relation between REM sleep and dreaming. Thus, REM is taken as a marker for dreaming and as REM is distributed ubiquitously throughout the mammalian class, it is suggested that other mammals also dream. It is suggested that the overall function of REM sleep/dreaming is more important than the content of the individual dream; its function is to place the dreamer protagonist/observer on the topographical world. This has importance for the developing infant who needs to develop a sense of self and separateness from the world which it requires to navigate and from which it is separated for long periods in sleep. Dreaming may also serve to maintain a sense of ‘I’ness or “self” in the adult, in whom a fragility of this faculty is revealed in neurological disorders.

  9. FTIR assessment of the effect of Ginkgo biloba leave extract (EGb 761) on mammalian retina.

    PubMed

    Gamal, Eman M; Aly, Eman M; Mahmoud, Sherif S; Talaat, Mona S; Sallam, Abdel Sattar M

    2011-09-01

    Ginkgo biloba extract has been therapeutically used for several decades to increase peripheral and cerebral blood flow as well as for the treatment of dementia. The extract contains multiple compounds such as flavonoids and terpenoids that are thought to contribute to its neuroprotective and vasotropic effects. In this study, we investigated the effect of prolonged administration of EGb 761, up to 10 weeks, on mammalian retina using Fourier transform infrared spectroscopy (FTIR). Two main groups were involved in this study: the normal group (n = 10); and EGb-administrated group (n = 50) that received-orally-a dose of 40 mg/kg/day EGb 761. The results demonstrated that EGb administration was associated with different beneficial effects on the retinal constituents especially the underlying amide I protein secondary structure components as well as the NH-OH region. It concluded that the optimum daily administration period of EGb (40 mg/kg) for ophthalmic applications that targeting the retina ranges from 5 to 8 weeks.

  10. Effects of crosslinking on the thermal stability of hemoglobin. I. The use of bis(3,5-dibromosalicyl) fumarate.

    PubMed

    White, F L; Olsen, K W

    1987-10-01

    The double-headed aspirin, bis(3,5-dibromosalicyl) fumarate, has been used to crosslink hemoglobin A between Lys 82 beta 1 and Lys 82 beta 2 (J. A. Walder et al. (1979) Biochemistry 18,4265). Denaturation experiments were used to compare the stability of this crosslinked protein to that of hemoglobin A. Thermal denaturations, done in 0.01 M 4-morpholine-propanesulfonic acid, pH 7, containing 0.9 M guanidine to prevent precipitation at high temperatures, were monitored by changes in absorbance between 190 and 650 nm using a diode array spectrophotometer. The sample was heated from 25 to 70 degrees C at 0.3 degrees C/min. The data were analyzed by using both a two-state model and a novel first derivative method. As expected, methemoglobin A had a single, broad transition with a midpoint of 40.7 degrees C. The crosslinked methemoglobin showed a transition at 57.1 degrees C. Two minor transitions, one of which was apparently due to residual unmodified hemoglobin, were also observed in the crosslinked sample. Thus, a single crosslink between only two of the four subunits can lead to a significantly more stable molecule. These results can be explained by Le Chatelier's principle, since crosslinking prevents dissociation of the beta-subunits and, thereby, holds the entire tetramer together.

  11. Effect of pH on Structural Changes in Perch Hemoglobin that Can Alter Redox Stability and Heme Affinity

    SciTech Connect

    Richards, Mark P.; Aranda, IV, Roman; He, Cai; Phillips, Jr., George N.

    2010-01-07

    pH can be manipulated to alter the oxidative stability of fish-based foods during storage. X-ray diffraction was used to investigate the ability of reduced pH to cause structural changes in fish hemoglobins that lead to enhanced oxidative degradation. Decreasing pH from 8.0 to 6.3 and 5.7 created a large channel for solvent entry into the heme crevice of perch hemoglobin beta chains. The proton-induced opening of this channel occurred between site CD3 and the heme-6-propionate. Solvent entry into the heme crevice can enhance metHb formation and hemin loss, processes that accelerate lipid oxidation. Reduced pH also decreased the distance between Ile at E11 in one of the alpha chains and the ligand above the heme iron atom. This sterically displaces O{sub 2} and protonated O{sub 2} which increases metHb formation. These studies demonstrate that pH reduction causes structural changes in perch hemoglobin which increase oxidative degradation of the heme pigment.

  12. Effects of Simultaneous Radiofrequency Radiation and Chemical Exposure of Mammalian Cells. Volume 2

    DTIC Science & Technology

    1988-07-01

    genotoxic chemical will result in an alteration of the genotoxic activity of the chemical alone., For 4-hr pulsed wave RP.F exposures at 2.45 GHz...RFR) in the microwave range, and specifically at 2.45 GHz (pulsed wave ), at moderate power levels and specific absorption rates, was genotoxic in...a) that RFR by itself is genotoxic to mammalian cells in vitro; and b) that a simultaneous exposure of mammalian cells to RFR during treatment with a

  13. Plasticizer endocrine disruption: Highlighting developmental and reproductive effects in mammals and non-mammalian aquatic species.

    PubMed

    Mathieu-Denoncourt, Justine; Wallace, Sarah J; de Solla, Shane R; Langlois, Valerie S

    2015-08-01

    Due to their versatility, robustness, and low production costs, plastics are used in a wide variety of applications. Plasticizers are mixed with polymers to increase flexibility of plastics. However, plasticizers are not covalently bound to plastics, and thus leach from products into the environment. Several studies have reported that two common plasticizers, bisphenol A (BPA) and phthalates, induce adverse health effects in vertebrates; however few studies have addressed their toxicity to non-mammalian species. The aim of this review is to compare the effects of plasticizers in animals, with a focus on aquatic species. In summary, we identified three main chains of events that occur in animals exposed to BPA and phthalates. Firstly, plasticizers affect development by altering both the thyroid hormone and growth hormone axes. Secondly, these chemicals interfere with reproduction by decreasing cholesterol transport through the mitochondrial membrane, leading to reduced steroidogenesis. Lastly, exposure to plasticizers leads to the activation of peroxisome proliferator-activated receptors, the increase of fatty acid oxidation, and the reduction in the ability to cope with the augmented oxidative stress leading to reproductive organ malformations, reproductive defects, and decreased fertility.

  14. Effect of Smoking During Radiotherapy, Respiratory Insufficiency, and Hemoglobin Levels on Outcome in Patients Irradiated for Non-Small-Cell Lung Cancer

    SciTech Connect

    Rades, Dirk Setter, Cornelia M.S.; Schild, Steven E.; Dunst, Juergen

    2008-07-15

    Purpose: To investigate the effect of smoking during radiotherapy (RT), respiratory insufficiency before RT, hemoglobin levels during RT, and additional factors on overall survival, locoregional control (LRC), and metastasis-free survival in non-small-cell lung cancer patients. Methods and Materials: The following factors were investigated in 181 patients who underwent RT for non-small-cell lung cancer: age, gender, Karnofsky performance score, histologic type, grade, T/N stage, American Joint Committee on Cancer stage, surgery, chemotherapy, respiratory insufficiency before RT, pack-years, smoking during RT, and hemoglobin levels during RT. Additionally, in the 129 patients who did not undergo surgery, the effect of the equivalent dose in 2-Gy fractions (EQD2) (<60 Gy vs. 60 Gy vs. >60 Gy) on outcome was investigated. Results: On multivariate analysis, improved overall survival was associated with a lower T stage (p = 0.004), lower N stage (p 0.040), surgery (p = 0.010), and no respiratory insufficiency (p = 0.023). A Karnofsky performance score >70 achieved borderline significance (p = 0.056). Improved LRC was associated with a lower T stage (p = 0.007) and no smoking during RT (p = 0.029). Improved metastasis-free survival was associated with lower T stage (p < 0.001) and lower N stage (p < 0.001). In those patients who did not undergo surgery, an EQD2 of {>=}60 Gy was associated with a better outcome than an EQD2 of <60 Gy. Furthermore, an EQD2 >60 Gy resulted in better LRC than did an EQD2 of {<=}60 Gy. Conclusions: Smoking during RT had a significant effect on LRC, but we did not find that hemoglobin levels or respiratory insufficiency significantly affected LRC or metastasis-free survival in our patient population. Furthermore, our data suggest a dose-effect relationship in those patients who did not undergo surgery.

  15. Hemoglobin parameters from diffuse reflectance data.

    PubMed

    Mourant, Judith R; Marina, Oana C; Hebert, Tiffany M; Kaur, Gurpreet; Smith, Harriet O

    2014-03-01

    Tissue vasculature is altered when cancer develops. Consequently, noninvasive methods of monitoring blood vessel size, density, and oxygenation would be valuable. Simple spectroscopy employing fiber optic probes to measure backscattering can potentially determine hemoglobin parameters. However, heterogeneity of blood distribution, the dependence of the tissue-volume-sampled on scattering and absorption, and the potential compression of tissue all hinder the accurate determination of hemoglobin parameters. We address each of these issues. A simple derivation of a correction factor for the absorption coefficient, μa, is presented. This correction factor depends not only on the vessel size, as others have shown, but also on the density of blood vessels. Monte Carlo simulations were used to determine the dependence of an effective pathlength of light through tissue which is parameterized as a ninth-order polynomial function of μa. The hemoglobin bands of backscattering spectra of cervical tissue are fit using these expressions to obtain effective blood vessel size and density, tissue hemoglobin concentration, and oxygenation. Hemoglobin concentration and vessel density were found to depend on the pressure applied during in vivo acquisition of the spectra. It is also shown that determined vessel size depends on the blood hemoglobin concentration used.

  16. Genomic imprinting is a parental effect established in mammalian germ cells.

    PubMed

    Li, Xiajun

    2013-01-01

    Genomic imprinting is an epigenetic phenomenon in which either the paternal or the maternal allele of imprinted genes is expressed in somatic cells. It is unique to eutherian mammals, marsupials, and flowering plants. It is absolutely required for normal mammalian development. Dysregulation of genomic imprinting can cause a variety of human diseases. About 150 imprinted genes have been identified so far in mammals and many of them are clustered such that they are coregulated by a cis-acting imprinting control region, called the ICR. One hallmark of the ICR is that it contains a germ line-derived differentially methylated region that is methylated on the paternal chromosome or on the maternal chromosome. The DNA methylation imprint is reset in the germ line and differential methylation at an ICR is restored upon fertilization. The DNA methylation imprint is resistant to a genome-wide demethylation process in early embryos and is stably maintained in postimplantation embryos. Maintenance of the DNA methylation imprint is dependent on two distinct maternal effect genes (Zfp57 and PGC7/Stella). In germ cells, around midgestation, the DNA methylation imprint is erased and undergoes another round of the DNA methylation imprint cycle that includes erasure, resetting, restoration, and maintenance of differential DNA methylation.

  17. Effect of mammalian kidney osmolytes on the folding pathway of sheep serum albumin.

    PubMed

    Dar, Mohammad Aasif; Islam, Asimul; Hassan, Md Imtaiyaz; Ahmad, Faizan

    2017-04-01

    Recently, we had published that urea-induced denaturation curves of optical properties of sheep serum albumin (SSA) are biphasic with a stable intermediate that has characteristics of molten globule (MG) state. In this study, we have extended the work by carrying out urea- and guanidinium chloride (GdmCl)-induced denaturations of SSA in the presence of naturally occurring mammalian kidney osmolytes, namely, sorbitol, myo-inositol and glycine betaine. We have observed that all these osmolytes (i) transform this biphasic transition into a co-operative, two-state transition and (ii) increase the stability of the protein in terms of midpoint of denaturation (Cm) and Gibbs free energy change in the absence of both denaturants (ΔGD(0)). The relative effectiveness of different osmolytes on the stability of SSA follows the order: glycine betaine>myo-inositol>sorbitol. In this paper, we also report that kidney osmolytes destabilize MG state by shifting the equilibrium, native state↔MG state toward the left. This study will be helpful in understanding the existence of osmolytes in kidney and their role in folding of kidney proteins soaked with urea.

  18. The effect of antidiuretic hormone on solute flows in mammalian collecting tubules

    PubMed Central

    Schafer, James A.; Andreoli, Thomas E.

    1972-01-01

    These experiments were intended to evaluate the antidiuretic hormone (ADH)-dependent reflection coefficients of urea, sucrose, and NaCl in cortical and outer medullary collecting tubules isolated from mammalian kidney. In one group of experiments, the ADH-dependent osmotic water flows, when the perfusing solutions contained hypotonic NaCl solutions, were indistinguishable from control observations when either urea or sucrose replaced, in part, NaCl in isotonic bathing solutions (cortical collecting tubules). Similarly, both in cortical and outer medullary collecting tubules exposed to ADH, there was zero net osmotic volume flow when a portion of the NaCl in the bathing and/or perfusing solutions was replaced by either sucrose or urea, so long as the perfusing and bathing solutions were isosmolal. Taken together, these observations suggest that the ADH-dependent reflection coefficients of NaCl, urea, and sucrose, in these tubules, were identical. Since the effective hydrodynamic radii of urea and sucrose are, respectively, 1.8 and 5.2 A, it is likely that σi, for urea, sucrose, and NaCl, was unity. In support of this, the diffusion permeability coefficient (PDi cm sec-1) of urea was indistinguishable from zero. Since the limiting sites for urea penetration were the luminal interfaces of the tubules, these data are consistent with the view that ADH increases diffusional water flow across such interfaces. Images PMID:5057132

  19. The effects of nerve stimulation and hemicholinium on synaptic vesicles at the mammalian neuromuscular junction

    PubMed Central

    Jones, S. F.; Kwanbunbumpen, Suthiwan

    1970-01-01

    1. Electron micrographs of nerve terminals in rat phrenic nerve—diaphragm preparations have been studied. This has been done before and after prolonged nerve stimulation. The effectiveness of nerve stimulation has been monitored by intracellular micro-electrode recordings from the muscle cells. 2. Characteristic changes in the form and distribution of the nerve terminal mitochondria were noted after nerve stimulation. 3. Synaptic vesicle numbers in the region of nerve terminal less than 1800 Å from the synaptic cleft were significantly greater in tissue taken 2 and 3 min after nerve stimulation, than in unstimulated preparations. 4. The long and short diameters of the synaptic vesicle profiles less than 1800 Å from the synaptic cleft were measured. Analysis of the distribution of the diameters indicated synaptic vesicles to be basically spherical structures. Estimates of synaptic vesicle volume were made from the measurements. Synaptic vesicle volume was significantly reduced in tissue taken 2 and 4 min following nerve stimulation. 5. If hemicholinium, a compound which inhibits acetylcholine synthesis, was present during the period of nerve stimulation, much greater reductions in synaptic vesicle volume occurred. Synaptic vesicle numbers in the region of nerve terminal less than 1800 Å from the synaptic cleft were also reduced, compared with unstimulated control preparations. 6. These results are regarded as support for the hypothesis that the synaptic vesicles in nerve terminals at the mammalian neuromuscular junction represent stores of the transmitter substance, acetylcholine. ImagesABABPlate 2AB PMID:5503879

  20. The lack of consistent diaspirin cross-linked hemoglobin infusion blood pressure effects in the US and EU traumatic hemorrhagic shock clinical trials.

    PubMed

    Sloan, Edward P; Philbin, Nora B; Koenigsberg, Max D; Gao, Weihua

    2010-02-01

    Hemoglobin solutions have demonstrated a pressor effect that could adversely affect hemorrhagic shock patient resuscitation through accelerated hemorrhage, diminished perfusion, or inadequate resuscitation. Data from two parallel, multicenter traumatic hemorrhagic shock clinical trials in 17 US emergency departments and in 27 EU prehospital systems using diaspirin cross-linked hemoglobin (DCLHb), a hemoglobin-based resuscitation fluid. In the 219 patients, patients were 37 years old, 64% sustained blunt injury, 48% received DCLHb, and 36% expired. Although mean systolic blood pressure (SBP) and diastolic blood pressure values differed at 2 of the 10 measured time points, blood pressure (BP) curve analysis showed no SBP, diastolic blood pressure, or MAP differences based on treatment. Although SBP values 160 and 120 mmHg or greater were 2.2x and 2.6x more frequently noted in survivors, they were not more common with DCLHb use or in DCLHb patients who expired in US study nonsurvivors or in any EU study patients. Systolic blood pressure values 160 and 120 mmHg or greater were 2.8x and 1.3x more frequently noted in DCLHb survivors as compared with normal saline survivors. Only 3% of the BP variation noted could be attributed to DCLHb use, and as expected, injury severity and baseline physiologic status were stronger predictors. In the United States alone, treatment group was not correlated by regression with BP at any time point. Neither mean BP readings nor elevated BP readings were correlated with DCLHb treatment of traumatic hemorrhagic shock patients. As such, no clinically demonstrable DCLHb pressor effect could be directly related to the adverse mortality outcome observed in the US study.

  1. Rice (Oryza) hemoglobins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice (Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a sin...

  2. Rice ( Oryza) hemoglobins

    PubMed Central

    Arredondo-Peter, Raúl; Moran, Jose F.; Sarath, Gautam

    2014-01-01

    Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice ( Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a single copy of the thb gene exist in Oryza sativa var. indica and O. sativa var. japonica, Hb transcripts coexist in rice organs and Hb polypeptides exist in rice embryonic and vegetative organs and in the cytoplasm of differentiating cells. At the structural level, the crystal structure of rice Hb1 has been elucidated, and the structures of the other rice Hbs have been modeled. Kinetic analysis indicated that rice Hb1 and 2, and possibly rice Hb3 and 4, exhibit a very high affinity for O 2, whereas rice Hb5 and tHb possibly exhibit a low to moderate affinity for O 2. Based on the accumulated information on the properties of rice Hbs and data from the analysis of other plant and non-plant Hbs, it is likely that Hbs play a variety of roles in rice organs, including O 2-transport, O 2-sensing, NO-scavenging and redox-signaling. From an evolutionary perspective, an outline for the evolution of rice Hbs is available. Rice nshb and thb genes vertically evolved through different lineages, rice nsHbs evolved into clade I and clade II lineages and rice nshbs and thbs evolved under the effect of neutral selection. This review also reveals lacunae in our ability to completely understand rice Hbs. Primary lacunae are the absence of experimental information about the precise functions of rice Hbs, the properties of modeled rice Hbs and the cis-elements and trans-acting factors that regulate the expression of rice hb genes, and the partial understanding of the evolution of rice Hbs. PMID:25653837

  3. Rice ( Oryza) hemoglobins.

    PubMed

    Arredondo-Peter, Raúl; Moran, Jose F; Sarath, Gautam

    2014-01-01

    Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice ( Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a single copy of the thb gene exist in Oryza sativa var. indica and O. sativa var. japonica, Hb transcripts coexist in rice organs and Hb polypeptides exist in rice embryonic and vegetative organs and in the cytoplasm of differentiating cells. At the structural level, the crystal structure of rice Hb1 has been elucidated, and the structures of the other rice Hbs have been modeled. Kinetic analysis indicated that rice Hb1 and 2, and possibly rice Hb3 and 4, exhibit a very high affinity for O 2, whereas rice Hb5 and tHb possibly exhibit a low to moderate affinity for O 2. Based on the accumulated information on the properties of rice Hbs and data from the analysis of other plant and non-plant Hbs, it is likely that Hbs play a variety of roles in rice organs, including O 2-transport, O 2-sensing, NO-scavenging and redox-signaling. From an evolutionary perspective, an outline for the evolution of rice Hbs is available. Rice nshb and thb genes vertically evolved through different lineages, rice nsHbs evolved into clade I and clade II lineages and rice nshbs and thbs evolved under the effect of neutral selection. This review also reveals lacunae in our ability to completely understand rice Hbs. Primary lacunae are the absence of experimental information about the precise functions of rice Hbs, the properties of modeled rice Hbs and the cis-elements and trans-acting factors that regulate the expression of rice hb genes, and the partial understanding of the evolution of rice Hbs.

  4. Different sensitivities of cultured mammalian cells towards aphidicolin-enhanced DNA effects in the comet assay.

    PubMed

    Speit, Günter; Schütz, Petra; Bausinger, Julia

    2016-06-01

    The comet assay in combination with the polymerase inhibitor aphidicolin (APC) has been used to measure DNA excision repair activity, DNA repair kinetics and individual DNA repair capacity. Since APC can enhance genotoxic effects of mutagens measured by the comet assay, this approach has been proposed for increasing the sensitivity of the comet assay in human biomonitoring. The APC-modified comet assay has mainly been performed with human blood and it was shown that it not only enhances the detection of DNA damage repaired by nucleotide excision repair (NER) but also damage typically repaired by base excision repair (BER). Recently, we reported that in contrast to blood leukocytes, A549 cells (a human lung adenocarcinoma cell line) seem to be insensitive towards the repair-inhibiting action of APC. To further elucidate the general usefulness of the APC-modified comet assay for studying repair in cultured mammalian cells, we comparatively investigated further cell lines (HeLa, TK6, V79). DNA damage was induced by BPDE (benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide) and MMS (methyl methanesulfonate) in the absence and presence of APC (3 or 15μM). APC was either added for 2h together with the mutagen or cells were pre-incubated for 30min with APC before the mutagen was added. The results indicate that the cell lines tested differ fundamentally with regard to their sensitivity and specificity towards the repair-inhibiting effect of APC. The actual cause for these differences is still unclear but potential molecular explanations are discussed. Irrespective of the underlying mechanism(s), our study revealed practical limitations of the use of the APC-modified comet assay.

  5. Effects of lead shot ingestion on delta-aminolevulinic acid dehydratase activity, hemoglobin concentration, and serum chemistry in bald eagles

    USGS Publications Warehouse

    Hoffman, D.J.; Pattee, O.H.; Wiemeyer, Stanley N.; Mulhern, B.

    1981-01-01

    Lead shot ingestion by bald eagles (Haliaeetus leucocephalus) is considered to be widespread and has been implicated in the death of eagles in nature. It was recently demonstrated under experimental conditions that ingestion of as few as 10 lead shot resulted in death within 12 to 20 days. In the present study hematological responses to lead toxicity including red blood cell ALAD activity, hemoglobin concentration and 23 different blood serum chemistries were examined in five captive bald eagles that were unsuitable for rehabilitation and release. Eagles were dosed by force-feeding with 10 lead shot; they were redosed if regurgitation occurred. Red blood cell ALAD activity was inhibited by nearly 80% within 24 hours when mean blood lead concentration had increased to 0.8 parts per million (ppm). By the end of 1 week there was a significant decrease (20-25%) in hematocrit and hemoglobin, and the mean blood lead concentration was over 3 ppm. Within as little as 1-2 weeks after dosing, significant elevations in serum creatinine and serum alanine aminotransferase occurred, as well as a significant decrease in the ratio of serum aspartic aminotransferase to serum alanine aminotransferase. The mean blood lead concentration was over 5 ppm by the end of 2 weeks. These changes in serum chemistry may be indicative of kidney and liver alterations.

  6. Effect of the hemoglobin-based oxygen carrier HBOC-201 on laboratory instrumentation: cobas integra, chiron blood gas analyzer 840, Sysmex SE-9000 and BCT.

    PubMed

    Wolthuis, A; Peek, D; Scholten, R; Moreira, P; Gawryl, M; Clark, T; Westerhuis, L

    1999-01-01

    As part of a clinical trial, we evaluated the effects of the hemoglobin-based oxygen-carrier (HBOC) HBOC-201 (an ultrapurified, stroma-free bovine hemoglobin product, Biopure, Cambridge, MA, USA) on our routine clinical chemistry analyzer (Cobas Integra, F. Hoffmann-La Roche Ltd, Basel, Switzerland ), blood gas analyzer (Chiron 840, Chiron Diagnostics Corporation, East Walpole, MA, USA), routine hemocytometry analyzer (Sysmex SE-9000, TOA Medical Electronics Co Ltd., Kobe, Japan), hemostasis analyzer (BCT, Dade-Behring, Marburg, Germany) and bloodbanking system (Dia-Med-ID Micro Typing System, DiaMed AG, Cressier, Switzerland). The maximum tested concentration of HBOC-201 was 65 g/l. Of the 27 routine clinical chemistry tests challenged with HBOC-201, bilirubin-direct, creatine kinase MB-fraction (CK-MB), creatine kinase (CK), gamma-glutamyltransferase (GGT), magnesium and uric acid were influenced by even low concentrations of HBOC-201. These tests were excluded from use on the plasma of patients treated with HBOC-201. Since the non-availability of the cardiac marker CK-MB may lead to problems in acute situations, we introduced the qualitative Trop T-test (Boehringer Mannheim), which was not influenced. The applicability of another nine tests was limited by the concentration of the HBOC-201 in the patients' plasma. No interference of HBOC-201 in routine hemocytometry, hemostasis-analysis and red-blood cell agglutination detection (blood-bank tests) was observed. Although immediate patient-care was not compromised, routine use of hemoglobin-based oxygen carriers will have a strong impact on logistical management. The development of robust laboratory tests free from the interference of the pigmented oxygen carriers should therefore precede its introduction into routine transfusion medicine.

  7. Effects of crosslinking on the thermal stability of hemoglobins. II. The stabilization of met-, cyanomet-, and carbonmonoxyhemoglobins A and S with bis(3,5-dibromosalicyl) fumarate.

    PubMed

    Yang, T; Olsen, K W

    1988-03-01

    Hemoglobins A and S were crosslinked between Lys 82 beta 1 and Lys 82 beta 2 using bis (3,5-dibromosalicyl) fumarate (J. A. Walder et al. (1979) Biochemistry 18, 4265). Thermal denaturation experiments were used to compare the stabilities of the met, cyanomet, and carbonmonoxy forms of these crosslinked hemoglobins to the corresponding uncrosslinked proteins. Uncrosslinked carbonmonoxy- and cyanomethemoglobins had transition temperatures about 11 degrees C higher than the corresponding met samples. The increase in denaturation temperature (Tm) due to crosslinking was 15 degrees C for the methemoglobins, 10 degrees C for the cyanomethemoglobins, and 4 degrees C for the carbonmonoxy ones. There was no significant difference in stability between the met and carbonmonoxy crosslinked proteins. In order of increasing stability the samples were: met Hb S less than met Hb A less than CO Hb S less than CO Hb A = CN-met Hb A less than met XL-Hb S = CO XL-Hb S less than met XL-Hb A = CO XL-Hb A less than CN-met XL-Hb A. The slight decrease in the stability of Hb S (beta 6 Glu----Val) compared to Hb A can be explained by the replacement of an external ionic group by a hydrophobic residue in Hb S. In mixtures of crosslinked and normal Hb A, the Tm of the uncrosslinked material was slightly increased by the presence of the more stable crosslinked hemoglobin. The effects of both crosslinking and cyanide or carbon monoxide binding can be explained by Le Chatelier's principle since both would favor the native form of the protein.

  8. Effects of Simulated Weightlessness on Mammalian Development. Part 2: Meiotic Maturation of Mouse Oocytes During Clinostat Rotation

    NASA Technical Reports Server (NTRS)

    Wolgemuth, D. J.; Grills, G. S.

    1985-01-01

    In order to understand the role of gravity in basic cellular processes that are important during development, the effects of a simulated microgravity environment on mammalian gametes and early embryos cultured in vitro are examined. A microgravity environment is simulated by use of a clinostat, which essentially reorients cells relative to the gravity vector. Initial studies have focused on assessing the effects of clinostat rotation on the meiotic progression of mouse oocytes. Modifications centered on providing the unique in vitro culture of the clinostat requirements of mammalian oocytes and embryos: 37 C temperature, constant humidity, and a 5% CO2 in air environment. The oocytes are observed under the dissecting microscope for polar body formation and gross morphological appearance. They are then processed for cytogenetic analysis.

  9. Biphasic effect of bimoclomol on calcium handling in mammalian ventricular myocardium

    PubMed Central

    Nánási, Péter P; Sárközi, Sándor; Szigeti, Gyula; Jóna, István; Szegedi, Csaba; Szabó, Ágnes; Bányász, Tamás; Magyar, János; Szigligeti, Péter; Körtvély, Ágnes; Csernoch, László; Kovács, László; Jednákovits, Andrea

    2000-01-01

    Concentration-dependent effects of bimoclomol, the novel heat shock protein coinducer, on intracellular calcium transients and contractility were studied in Langendorff-perfused guinea-pig hearts loaded with the fluorescent calcium indicator dye Fura-2. Bimoclomol had a biphasic effect on contractility: both peak left ventricular pressure and the rate of force development significantly increased at a concentration of 10 nM or higher. The maximal effect was observed between 0.1 and 1 μM, and the positive inotropic action disappeared by further increasing the concentration of bimoclomol. The drug increased systolic calcium concentration with a similar concentration-dependence. In contrast, diastolic calcium concentration increased monotonically in the presence of bimoclomol. Thus low concentrations of the drug (10–100 nM) increased, whereas high concentrations (10 μM) decreased the amplitude of intracellular calcium transients.Effects of bimoclomol on action potential configuration was studied in isolated canine ventricular myocytes. Action potential duration was increased at low (10 nM), unaffected at intermediate (0.1–1 μM) and decreased at high (10–100 μM) concentrations of the drug.In single canine sarcoplasmic calcium release channels (ryanodine receptor), incorporated into artificial lipid bilayer, bimoclomol significantly increased the open probability of the channel in the concentration range of 1–10 μM. The increased open probability was associated with increased mean open time. The effect of bimoclomol was again biphasic: the open probability decreased below the control level in the presence of 1 mM bimoclomol.Bimoclomol (10 μM–1 mM) had no significant effect on the rate of calcium uptake into sarcoplasmic reticulum vesicles of the dog, indicating that in vivo calcium reuptake might not substantially be affected by the drug.In conclusion, the positive inotropic action of bimoclomol is likely due to the activation of the

  10. Genotoxic effects of fly ash in bacteria, mammalian cells and animals.

    PubMed

    Morris, D L; Connor, T H; Harper, J B; Ward, J B; Legator, M S

    1989-01-01

    The increasing use of fossil fuels has raised concerns about possible deleterious health effects of the final combustion product, fly ash. Seven ash samples from coal sources obtained from Battelle Columbus Laboratories were evaluated in the Salmonella/mammalian microsome mutagenicity assay to determine their mutagenic potential. While dimethyl sulfoxide extracts of five samples showed no mutagenicity, sample 102 caused an increase in the number of revertants per plate over controls in TA100 and TA98 with activation by liver homogenate (2-fold and 2.4-fold, respectively), and without (2-fold and 6-fold). This ash was thus evaluated in whole animal studies. Animals treated by inhalation or oral gavage were assayed for the presence of mutagens in the urine, micronuclei in polychromatic erythrocytes, and chromosomal aberrations in metaphase bone marrow cells. Those animals treated by inhalation were also examined for local damage in the lung. The assay for mutagens in the urine was negative as shown by the Ames assay with TA100 and TA98 and there was no increase in micronuclei or in metaphase aberrations. Histological sections from the animals treated by inhalation did not show the presence of particles, macrophage infiltrations and generalized lung damage. We tested the same fly ash with an in vitro cell transformation assay with the cell line Balb/c 3T3 subclone A31-1-13. Although there was not an increase in Type III foci, there was a dose-dependent increase of Type II foci in the treated cells over the controls. In one assay, there was approximately a 14-fold increase in Type II foci in the highest dose (2 mg/ml) compared to the solvent control. One other ash sample induced cell transformation without being markedly cytotoxic, while a third sample was highly toxic but did not induce transformation.

  11. Cytotoxic and clastogenic effects of soluble chromium compounds on mammalian cell cultures.

    PubMed Central

    Levis, A. G.; Majone, F.

    1979-01-01

    The inhibition of cell growth, the reduction of cell survival and the induction of chromosome aberrations and of sister chromatid exchange (SCE) have been determined in cultured hamster cell lines (BHK and CHO) treated with 11 water-soluble compounds of hexavalent and trivalent chromium. All Cr6+ compounds inhibit growth of BHK cells and reduce survival of CHO cells to levels comparable to those obtained only after exposure to 100--1000 times higher Cr3+ concentrations. The cytotoxicity curves obtained with the different Cr6+ compounds are almost overlapping, whereas marked differences of activity are noticeable among Cr3+ compounds. Giant cells are obtained after exposure to Cr6+ and Cr3+ compounds, as shown by the rise of DNA and RNA per cell, and are due to the blockage of the cell cycle without sudden inhibition of macromolecular syntheses. Both Cr6+ and Cr3+ compounds are able to induce chromosome aberrations, whereas Cr3+ is absolutely incapable of inducing SCE, only Cr6+ being active. The frequency of chromosome aberrations is increased about 10-fold after exposure to 1.0 micrograms/ml Cr6+, whereas it is only doubled after treatment with up to 150 micrograms/ml Cr3+. On the other hand, in spite of the sensitivity of CHO cells to the induction of SCE by mitomycin C, the frequency of SCE hardly doubles after exposure to Cr6+ compounds. The present data confirm that Cr6+ compounds are characterized by a marked cytotoxicity and clastogenic action on mammalian cell cultures and show that Cr3+ compounds, though cytotoxic only at extremely high concentrations and not increasing the frequency of SCE, are not completely without cytogenetic effect, as they are able to induce chromosome aberrations. PMID:497104

  12. Mammalian pheromones.

    PubMed

    Liberles, Stephen D

    2014-01-01

    Mammalian pheromones control a myriad of innate social behaviors and acutely regulate hormone levels. Responses to pheromones are highly robust, reproducible, and stereotyped and likely involve developmentally predetermined neural circuits. Here, I review several facets of pheromone transduction in mammals, including (a) chemosensory receptors and signaling components of the main olfactory epithelium and vomeronasal organ involved in pheromone detection; (b) pheromone-activated neural circuits subject to sex-specific and state-dependent modulation; and (c) the striking chemical diversity of mammalian pheromones, which range from small, volatile molecules and sulfated steroids to large families of proteins. Finally, I review (d) molecular mechanisms underlying various behavioral and endocrine responses, including modulation of puberty and estrous; control of reproduction, aggression, suckling, and parental behaviors; individual recognition; and distinguishing of own species from predators, competitors, and prey. Deconstruction of pheromone transduction mechanisms provides a critical foundation for understanding how odor response pathways generate instinctive behaviors.

  13. Mammalian Pheromones

    PubMed Central

    Liberles, Stephen D.

    2015-01-01

    Mammalian pheromones control a myriad of innate social behaviors and acutely regulate hormone levels. Responses to pheromones are highly robust, reproducible, and stereotyped and likely involve developmentally predetermined neural circuits. Here, I review several facets of pheromone transduction in mammals, including (a) chemosensory receptors and signaling components of the main olfactory epithelium and vomeronasal organ involved in pheromone detection; (b) pheromone-activated neural circuits subject to sex-specific and state-dependent modulation; and (c) the striking chemical diversity of mammalian pheromones, which range from small, volatile molecules and sulfated steroids to large families of proteins. Finally, I review (d ) molecular mechanisms underlying various behavioral and endocrine responses, including modulation of puberty and estrous; control of reproduction, aggression, suckling, and parental behaviors; individual recognition; and distinguishing of own species from predators, competitors, and prey. Deconstruction of pheromone transduction mechanisms provides a critical foundation for understanding how odor response pathways generate instinctive behaviors. PMID:23988175

  14. Increased nitrite reductase activity of fetal versus adult ovine hemoglobin

    PubMed Central

    Blood, Arlin B.; Tiso, Mauro; Verma, Shilpa T.; Lo, Jennifer; Joshi, Mahesh S.; Azarov, Ivan; Longo, Lawrence D.; Gladwin, Mark T.; Kim-Shapiro, Daniel B.; Power, Gordon G.

    2009-01-01

    Growing evidence indicates that nitrite, NO2−, serves as a circulating reservoir of nitric oxide (NO) bioactivity that is activated during physiological and pathological hypoxia. One of the intravascular mechanisms for nitrite conversion to NO is a chemical nitrite reductase activity of deoxyhemoglobin. The rate of NO production from this reaction is increased when hemoglobin is in the R conformation. Because the mammalian fetus exists in a low-oxygen environment compared with the adult and is exposed to episodes of severe ischemia during the normal birthing process, and because fetal hemoglobin assumes the R conformation more readily than adult hemoglobin, we hypothesized that nitrite reduction to NO may be enhanced in the fetal circulation. We found that the reaction was faster for fetal than maternal hemoglobin or blood and that the reactions were fastest at 50–80% oxygen saturation, consistent with an R-state catalysis that is predominant for fetal hemoglobin. Nitrite concentrations were similar in blood taken from chronically instrumented normoxic ewes and their fetuses but were elevated in response to chronic hypoxia. The findings suggest an augmented nitrite reductase activity of fetal hemoglobin and that the production of nitrite may participate in the regulation of vascular NO homeostasis in the fetus. PMID:19028797

  15. Effect of Vitreoscilla hemoglobin expression on growth and specific tissue plasminogen activator productivity in recombinant Chinese hamster ovary cells

    SciTech Connect

    Pendse, G.J.; Bailey, J.E. . Dept. of Chemical Engineering)

    1994-12-01

    Previous studies suggest that secretion of cloned proteins synthesized by recombinant Chinese hamster ovary (CHO) cells can be adenosine triphosphate (ATP) limited. Other research indicates that the presence of cloned Vitreoscilla hemoglobin (VHb) enhances ATP production in oxygen-limited Escherichia coli. To evaluate the influence of VHb expression on recombinant CHO cell productivity, the vhb gene has been fused to the mouse mammary tumor virus (MMTV) promoter and cloned in a CHO cell line previously engineered to express human tissue plasminogen activator (tPA). Western blot analysis confirms dexamethasone-inducible VHb expression in all of the clones tested. Batch cultivation experiments with one VHb-expressing clone and the parental CHO-tPA cells show a reduced specific growth rate in the VHb-expressing cells. The VHb-expressing clone exhibits specific tPA production 40 to 100% greater than the parental CHO-tPA culture.

  16. Angiographic and volumetric effects of mammalian target of rapamycin inhibitors on angiomyolipomas in tuberous sclerosis

    PubMed Central

    Sheth, Rahul A; Feldman, Adam S; Paul, Elahna; Thiele, Elizabeth A; Walker, T Gregory

    2016-01-01

    AIM: To investigate the angiographic and volumetric effects of mammalian target of rapamycin (mTOR) inhibitors on angiomyolipomas (AMLs) in a case series of patients with tuberous sclerosis complex. METHODS: All patients who underwent catheter angiography prior to and following mTOR inhibitor therapy (n = 3) were evaluated. All cross-sectional imaging studies were analyzed with three-dimensional volumetrics, and tumor volume curves for all three tissue compartments (soft tissue, vascular, and fat) were generated. Segmentation analysis tools were used to automatically create a region of interest (ROI) circumscribing the AML. On magnetic resonance images, the “fat only” map calculated from the in- and opposed-phase gradient recalled echo sequences was used to quantify fat volume within tumors. Tumor vascularity was measured by applying a thresholding tool within the ROI on post-contrast subtraction images. On computed tomography images, volume histogram analysis of Hounsfield unit was performed to quantify tumor tissue composition. The angiography procedures were also reviewed, and tumor vascularity based on pre-embolization angiography was characterized in a semi-quantitative manner. RESULTS: Patient 1 presented at the age of 15 with a 6.8 cm right lower pole AML and a 4.0 cm right upper pole AML. Embolization was performed of both tumors, and after a few years of size control, the tumors began to grow, and the patient was initiated on mTOR inhibitor therapy. There was an immediate reduction in the size of both lesions. The patient then underwent repeat embolization and discontinuation of mTOR inhibition, after which point there was a substantial regrowth in both tumors across all tissue compartments. Patient 2 presented at the age of 18 with a right renal AML. Following a brief period of tumor reduction after embolization, she was initiated on mTOR inhibitor therapy, with successful reduction in tumor size across all tissue compartments. As with patient 1

  17. Multiple hemoglobins of the cutthroat trout, Salmo clarki.

    PubMed

    Southard, J N; Berry, C R; Farley, T M

    1986-07-01

    Nine hemoglobins were purified from blood of Salmo clarki by ion-exchange chromatography and preparative isoelectric focusing. The subunit structures of eight of the purified hemoglobins were studied by electrophoresis of globins in the presence of urea. Six are alpha 2 beta 2 tetramers while two appear to be heterotetramers of the type alpha alpha' beta 2 and alpha alpha' beta beta'. The effects of pH, nucleotides, and temperature on the oxygen equilibria of the purified hemoglobins were studied. Five hemoglobins with isoelectric points from 9.1 to 7.1 and one minor hemoglobin with an isoelectric point of 5.9 appear to have essentially identical oxygen binding properties. All have similar oxygen equilibria which are independent of pH and temperature and not affected by saturating amounts of ATP. Another minor hemoglobin with an isoelectric point below 5.9 has similar oxygen equilibria except for a possible pH dependence. Two hemoglobins, with isoelectric points of 6.5 and 6.4, have oxygen binding properties which are strongly pH and temperature dependent. Addition of ATP or GTP causes a large decrease in the oxygen affinity without affecting the cooperativity of oxygen binding. The effect of GTP is slightly greater than that of ATP. No significant differences were observed in the oxygen equilibria of these two hemoglobins. The red blood cells of S. clarki were found to contain large amounts of both ATP and GTP, with an ATP:GTP ratio of 3:1. Both nucleotides may be important modulators of hemoglobin oxygen affinity in S. clarki, in contrast to the situation in S. gairdneri, in which red blood cell GTP concentrations are considerably lower. The presence of six or possibly seven hemoglobins with identical oxygen binding properties in S. clarki suggests that, to a large extent, the physiological role of multiple hemoglobins in this species involves phenomena not directly related to the oxygen binding properties of the hemoglobins.

  18. Mammalian collection on Noah's Ark: the effects of beauty, brain and body size.

    PubMed

    Frynta, Daniel; Šimková, Olga; Lišková, Silvie; Landová, Eva

    2013-01-01

    The importance of today's zoological gardens as the so-called "Noah's Ark" grows as the natural habitat of many species quickly diminishes. Their potential to shelter a large amount of individuals from many species gives us the opportunity to reintroduce a species that disappeared in nature. However, the selection of animals to be kept in zoos worldwide is highly selective and depends on human decisions driven by both ecological criteria such as population size or vulnerability and audience-driven criteria such as aesthetic preferences. Thus we focused our study on the most commonly kept and bred animal class, the mammals, and we asked which factors affect various aspects of the mammalian collection of zoos. We analyzed the presence/absence, population size, and frequency per species of each of the 123 mammalian families kept in the worldwide zoo collection. Our aim was to explain these data using the human-perceived attractiveness of mammalian families, their body weight, relative brain size and species richness of the family. In agreement with various previous studies, we found that the body size and the attractiveness of mammals significantly affect all studied components of the mammalian collection of zoos. There is a higher probability of the large and attractive families to be kept. Once kept, these animals are presented in larger numbers in more zoos. On the contrary, the relative mean brain size only affects the primary selection whether to keep the family or not. It does not affect the zoo population size or the number of zoos that keep the family.

  19. Mammalian Collection on Noah's Ark: The Effects of Beauty, Brain and Body Size

    PubMed Central

    Frynta, Daniel; Šimková, Olga; Lišková, Silvie; Landová, Eva

    2013-01-01

    The importance of today's zoological gardens as the so-called “Noah's Ark” grows as the natural habitat of many species quickly diminishes. Their potential to shelter a large amount of individuals from many species gives us the opportunity to reintroduce a species that disappeared in nature. However, the selection of animals to be kept in zoos worldwide is highly selective and depends on human decisions driven by both ecological criteria such as population size or vulnerability and audience-driven criteria such as aesthetic preferences. Thus we focused our study on the most commonly kept and bred animal class, the mammals, and we asked which factors affect various aspects of the mammalian collection of zoos. We analyzed the presence/absence, population size, and frequency per species of each of the 123 mammalian families kept in the worldwide zoo collection. Our aim was to explain these data using the human-perceived attractiveness of mammalian families, their body weight, relative brain size and species richness of the family. In agreement with various previous studies, we found that the body size and the attractiveness of mammals significantly affect all studied components of the mammalian collection of zoos. There is a higher probability of the large and attractive families to be kept. Once kept, these animals are presented in larger numbers in more zoos. On the contrary, the relative mean brain size only affects the primary selection whether to keep the family or not. It does not affect the zoo population size or the number of zoos that keep the family. PMID:23690985

  20. The effects of non-thermal plasmas on selected mammalian cells

    NASA Astrophysics Data System (ADS)

    Leduc, Mathieu

    Non-thermal plasma surface modifications have become indispensable processing steps in various industry and research sectors. Applications range from semiconductor processing to biotechnology and recently, plasma medicine. Non-thermal plasma sources have the advantage that a number of electron-driven chemical reactions can be produced while maintaining the gas (heavy species) temperature low, thus enabling the treatment of temperature-sensitive surfaces such as polymers, tissues and live cells. In the fields of biology and medicine, non-thermal plasmas have been primarily used for the deposition or modification of biocompatible polymers and for sterilization. Recently, non-thermal plasmas have been used to treat tissues and cells. A new field of research has emerged, Plasma Medicine, which studies the effects of non-thermal plasmas on cells and tissues for clinical applications. The Atmospheric Pressure Glow Discharge torch (APGD-t), a non-thermal plasma source, built in our laboratory was used to study the effects of non-thermal plasmas on mammalian cells. In its first application, we indirectly used the APGD-t to deposit a plasma-polymer on a glass surface and studied its effects on cultured cells. It was shown that the cells grew preferentially on the plasma-polymer, and their proliferation rate increased. The second application of the APGD-t was to further investigate previous observations of cell permeabilization obtained by plasma treatments and to apply non-thermal plasmas to cell transfection. It was demonstrated that the APGD-t is able to locally transfect adherent cells. We estimated the diameter of the pores created to be below 10 nm and that the pores remain open for less than 5 seconds. However, while investigating the mechanisms involved in cell transfection we observed that the use of higher gas flows in the negative controls (using the APGD-t but with the plasma turned off) also resulted in cell transfection. To further study this phenomena, we

  1. Effect of Dietary Oxalate on the Gut Microbiota of the Mammalian Herbivore Neotoma albigula

    PubMed Central

    Oakeson, Kelly F.; Dale, Colin; Dearing, M. Denise

    2016-01-01

    Diet is one of the primary drivers that sculpts the form and function of the mammalian gut microbiota. However, the enormous taxonomic and metabolic diversity held within the gut microbiota makes it difficult to isolate specific diet-microbe interactions. The objective of the current study was to elucidate interactions between the gut microbiota of the mammalian herbivore Neotoma albigula and dietary oxalate, a plant secondary compound (PSC) degraded exclusively by the gut microbiota. We quantified oxalate degradation in N. albigula fed increasing amounts of oxalate over time and tracked the response of the fecal microbiota using high-throughput sequencing. The amount of oxalate degraded in vivo was linearly correlated with the amount of oxalate consumed. The addition of dietary oxalate was found to impact microbial species diversity by increasing the representation of certain taxa, some of which are known to be capable of degrading oxalate (e.g., Oxalobacter spp.). Furthermore, the relative abundances of 117 operational taxonomic units (OTU) exhibited a significant correlation with oxalate consumption. The results of this study indicate that dietary oxalate induces complex interactions within the gut microbiota that include an increase in the relative abundance of a community of bacteria that may contribute either directly or indirectly to oxalate degradation in mammalian herbivores. PMID:26896138

  2. Effects of large mammalian herbivores and ant symbionts on condensed tannins of Acacia drepanolobium in Kenya.

    PubMed

    Ward, David; Young, Truman P

    2002-05-01

    Condensed tannins have been considered to be important inducible defenses against mammalian herbivory. We tested for differences in condensed tannin defenses in Acacia drepanolobium in Kenya over two years among different large mammalian herbivore treatments [total exclusion, antelope only, and megaherbivore (elephants and giraffes) + antelope] and with four different ant symbiont species on the trees. We predicted that (1) condensed tannin concentrations would be lowest in the mammal treatment with the lowest level of herbivory (total exclusion), (2) trees occupied by mutualist ants that protect the trees most aggressively would have lower levels of tannins, and (3) if chemical defense production is costly, there would be a trade-off between tannin concentrations, growth, and mechanical defenses. Mean tannin concentrations increased from total exclusion treatments to wildlife-only treatments to megaherbivore + antelope treatments. In 1997, condensed tannin concentrations were significantly lower in trees occupied by the ant Crematogaster nigriceps, the only ant species that actively removed axillary buds. Contrary to our prediction, trees occupied by ant species that protect the trees more aggressively against mammalian herbivores did not have lower overall levels of condensed tannins. There was no consistent evidence of a trade-off between tannin concentrations and growth rate, but there was a positive correlation between mean thorn length and mean tannin concentrations across species of ant inhabitants and across herbivore treatments in 1997. Contrary to our expectation, trees had higher tannin concentrations in the upper parts of the canopy where there is little herbivory by mammals.

  3. Effects of experimental reduction in nest micro-parasite and macro-parasite loads on nestling hemoglobin level in blue tits Parus caeruleus

    NASA Astrophysics Data System (ADS)

    Słomczyński, Robert; Kaliński, Adam; Wawrzyniak, Jarosław; Bańbura, Mirosława; Skwarska, Joanna; Zieliński, Piotr; Bańbura, Jerzy

    2006-09-01

    Theory suggests that macro- and micro-parasites may be important factors of selection for life-histories. They generate selection pressures by detrimental effects on host health. Nests of secondary cavity nesters provide a convenient habitat for an assemblage of parasites exploiting nestlings. In this study, natural blue tit Parus caeruleus nests (26) were replaced with clean artificial nests, twice during the nestling stage. This treatment caused an increase of 7-10.5 g/l in hemoglobin level of 12-day-old nestlings in comparison with control nestlings. Nestlings that developed in parasite-pathogen-free nests improved their health status. The experimental sterilization did not affect a morphometric index of condition. Potential effects on condition indices might be masked by trophic conditions.

  4. Effects of resuscitation with polymerized porcine hemoglobin (pPolyHb) on hemodynamic stability and oxygen delivery in a rat model of hemorrhagic shock.

    PubMed

    Wang, Li; Liu, Fang; Yan, Kunping; Pan, Wencan; Xu, Lijuan; Liu, Huifang; Yan, Chengbin; Chen, Chao; Zhu, Hongli

    2017-02-01

    The objective of this study was to evaluate the effects of polymerized porcine hemoglobin (pPolyHb) on hemodynamic stability and oxygen delivery in a rat model of hemorrhagic shock. Rats underwent controlled hemorrhage, resulting in the loss of 65% of their blood volume in 90 minutes. The results showed that pPolyHb was superior to hetastarch and saline, and similar to whole blood, in restoring hemodynamic stability and reversing anaerobic metabolism caused by hemorrhage. Furthermore, pPolyHb improved oxygen supply and increased blood oxygen content. These data suggest that pPolyHb can be effective in improving tissue perfusion under conditions of severe hemorrhagic shock.

  5. Hemoglobin Drift after Cardiac Surgery

    PubMed Central

    George, Timothy J.; Beaty, Claude A.; Kilic, Arman; Haggerty, Kara A.; Frank, Steven M.; Savage, William J.; Whitman, Glenn J.

    2013-01-01

    Introduction Recent literature suggests that a restrictive approach to red blood cell transfusions is associated with improved outcomes in cardiac surgery (CS) patients. Even in the absence of bleeding, intravascular fluid shifts cause hemoglobin levels to drift postoperatively, possibly confounding the decision to transfuse. We undertook this study to define the natural progression of hemoglobin levels in postoperative CS patients. Methods We included all CS patients from 10/10-03/11 who did not receive a postoperative transfusion. Primary stratification was by intraoperative transfusion status. Change in hemoglobin was evaluated relative to the initial postoperative hemoglobin. Maximal drift was defined as the maximum minus the minimum hemoglobin for a given hospitalization. Final drift was defined as the difference between initial and discharge hemoglobin. Results Our final cohort included 199 patients, 71(36%) received an intraoperative transfusion while 128(64%) did not. The average initial and final hemoglobin for all patients were 11.0±1.4g/dL and 9.9±1.3g/dL, respectively, an final drift of 1.1±1.4g/dL. The maximal drift was 1.8±1.1g/dL and was similar regardless of intraoperative transfusion status(p=0.9). Although all patients’ hemoglobin initially dropped, 79% of patients reached a nadir and experienced a mean recovery of 0.7±0.7g/dL by discharge. On multivariable analysis, increasing CPB time was significantly associated with total hemoglobin drift(Coefficient/hour: 0.3[0.1–0.5]g/dL, p=0.02). Conclusions In this first report of hemoglobin drift following CS, although all postoperative patients experienced downward hemoglobin drift, 79% of patients exhibited hemoglobin recovery prior to discharge. Physicians should consider the eventual upward hemoglobin drift prior to administering red cell transfusions. PMID:22609121

  6. Properties of Hemoglobin Decolorized with a Histidine-Specific Protease.

    PubMed

    Shi, Jing; de Roos, Andre; Schouten, Olaf; Zheng, Chaoya; Vink, Collin; Vonk, Brenda; Kliphuis, Annette; Schaap, Albert; Edens, Luppo

    2015-06-01

    This study investigated the application of Aspergilloglutamic peptidase (AGP) on porcine hemoglobin decolorization. AGP from fungus Aspergillus niger is identified to possess a high preference towards the histidine residues. As histidine residues in hemoglobin are known to coordinate the heme group within the globin molecule, we therefore hypothesized that incubating hemoglobin with a histidine-specific protease would efficiently separate the non-heme peptides from the heme-enriched peptides with a minimum degree of hydrolysis. AGP-decolored porcine hemoglobin hydrolysates were assessed on their functional (for example, color, emulsification, foaming, and water binding) and sensory properties. The results were compared with commercially available blood-derived proteins (subtilisin-decolored hemoglobin hydrolysates and plasma protein). It was observed that AGP is able to effectively decolor hemoglobin. The degree of hydrolysis (DH) increased less than 3% using AGP to achieve 90% color reduction of hemoglobin, whereas a DH increase of more than 20% is needed using subtilisin. The AGP-decolored hemoglobin hydrolysates (AGP-Hb) possess good emulsification, foaming, and water binding properties, which are better or comparable with the plasma protein, and much better than the subtilisin-decolored hemoglobin hydrolysates (subtilisin-Hb). The model canned meat with addition of AGP-Hb showed the highest value in hardness, springiness, and chewiness from the texture analysis. Furthermore, the canned meat with AGP-Hb was found to have a better sensory profile than the ones with addition of subtilisin-Hb and plasma protein.

  7. Effects of Overexpression of WRI1 and Hemoglobin Genes on the Seed Oil Content of Lepidium campestre

    PubMed Central

    Ivarson, Emelie; Leiva-Eriksson, Nélida; Ahlman, Annelie; Kanagarajan, Selvaraju; Bülow, Leif; Zhu, Li-Hua

    2017-01-01

    The wild species field cress (Lepidium campestre), belonging to the Brassicaceae family, has potential to be developed into a novel oilseed- and catch crop, however, the species needs to be further improved regarding some important agronomic traits. One of them is its low oil content which needs to be increased. As far as we know there is no study aiming at increasing the oil content that has been reported in this species. In order to investigate the possibility to increase the seed oil content in field cress, we have tried to introduce the Arabidopsis WRINKLED1 (AtWRI1) or hemoglobin (Hb) genes from either Arabidopsis thaliana (AtHb2) or Beta vulgaris (BvHb2) into field cress with the seed specific expression. The hypothesis was that the oil content would be increased by overexpressing these target genes. The results showed that the oil content was indeed increased by up to 29.9, 20.2, and 25.9% in the transgenic lines expressing AtWRI1, AtHb2, and BvHb2, respectively. The seed oil composition of the transgenic lines did not significantly deviate from the seed oil composition of the wild type plants. Our results indicate that genetic modification can be used in this wild species for its fast domestication into a future economically viable oilseed and catch crop. PMID:28119714

  8. Studies on the contributions of steric and polarity effects to the H2S-binding properties of Vitreoscilla hemoglobin

    NASA Astrophysics Data System (ADS)

    Wang, Dandan; Wang, Hui; Li, Haichao; Liu, Li; Li, Zhengqiang

    2017-01-01

    We have reported recently that Vitreoscilla hemoglobin (VHb) is a potential H2S receptor and storage molecule in bacterial metabolism. In this study, molecular cloning and site-directed mutagenesis were employed to investigate the structural basis for H2S binding. Association and dissociation rate constants (kon and koff) were determined using stopped-flow rapid-scanning spectrophotometry and compared with those for wild type VHb. Several unanticipated factors were found to govern H2S binding properties, due to the distinct structure of VHb. The results presented in this paper show that: i) bulkier residues at positions E7 and E11 decrease H2S binding accessibility, while the residue located at position B10 blocks bound H2S from escaping. ii) hydroxyl sidechains within the distal heme pocket reduce H2S reactivity to VHb; iii) Pro(E8) is involved in moving the E7-E10 loop region to trigger opening of the distal heme pocket to facilitate H2S binding.

  9. Effects of Overexpression of WRI1 and Hemoglobin Genes on the Seed Oil Content of Lepidium campestre.

    PubMed

    Ivarson, Emelie; Leiva-Eriksson, Nélida; Ahlman, Annelie; Kanagarajan, Selvaraju; Bülow, Leif; Zhu, Li-Hua

    2016-01-01

    The wild species field cress (Lepidium campestre), belonging to the Brassicaceae family, has potential to be developed into a novel oilseed- and catch crop, however, the species needs to be further improved regarding some important agronomic traits. One of them is its low oil content which needs to be increased. As far as we know there is no study aiming at increasing the oil content that has been reported in this species. In order to investigate the possibility to increase the seed oil content in field cress, we have tried to introduce the Arabidopsis WRINKLED1 (AtWRI1) or hemoglobin (Hb) genes from either Arabidopsis thaliana (AtHb2) or Beta vulgaris (BvHb2) into field cress with the seed specific expression. The hypothesis was that the oil content would be increased by overexpressing these target genes. The results showed that the oil content was indeed increased by up to 29.9, 20.2, and 25.9% in the transgenic lines expressing AtWRI1, AtHb2, and BvHb2, respectively. The seed oil composition of the transgenic lines did not significantly deviate from the seed oil composition of the wild type plants. Our results indicate that genetic modification can be used in this wild species for its fast domestication into a future economically viable oilseed and catch crop.

  10. [Contributions and prospects of hemoglobin derivatives].

    PubMed

    Remy, B; Deby-Dupont, G; Lamy, M

    1997-06-21

    shock and perioperative hemodilution. Experimental work in animals has afforded good results: restoration of normal O2 pressure and no toxicity. These assays allow frequent observation of an unexpected rapid hypertensive effect, transient, reversible, and that could be controlled by antihypertensive drugs. The mechanisms of this hypertensive effect remain controverted (stimulation of endothelin production, inhibition of nitric oxide effects, etc.). In humans, studies with healthy volunteers have been completed, while phase II clinical studies are under way in hypovolemic shock, in major abdominal, orthopedic and cardiac surgery, in stroke and in intensive care patients after surgery. The detailed results are awaited, but the modified hemoglobin solutions already appear to be without toxicity and present the same hypertensive effect as observed in animals. However, until now only low doses have been used, and the catabolism of these solutions remains largely unknown.

  11. [Hemoglobin H: laboratory identification].

    PubMed

    Ribeiro, V S; de Araújo, J T

    1992-01-01

    Hemoglobin H (Hb H) disease is an alpha thalassemia form characterized by low synthesis of alpha chain and high beta chain concentration; this unbalance induces the beta chain tetramers formation. Hb H is relatively frequent in Thailand and Greece. Isolated cases have been reported in Chinese, Filipinos, Malaysians. In the Near East occasional cases were observed in Greek Cypriots and Jordanian Arabs. Hb H carriers were found in Italy, Spain, Canada, Indonesia and other countries. In Brazil there are descendants of Italians, Chinese and people of negro origin who are carriers of Hb H. We identified the Hb H by electrophoresis, instability and characteristic inclusion bodies.

  12. Disorders of Human Hemoglobin

    NASA Astrophysics Data System (ADS)

    Bank, Arthur; Mears, J. Gregory; Ramirez, Francesco

    1980-02-01

    Studies of the human hemoglobin system have provided new insights into the regulation of expression of a group of linked human genes, the γ -δ -β globin gene complex in man. In particular, the thalassemia syndromes and related disorders of man are inherited anemias that provide mutations for the study of the regulation of globin gene expression. New methods, including restriction enzyme analysis and cloning of cellular DNA, have made it feasible to define more precisely the structure and organization of the globin genes in cellular DNA. Deletions of specific globin gene fragments have already been found in certain of these disorders and have been applied in prenatal diagnosis.

  13. Experimental recovery of intrinsic fluorescence and fluorophore concentration in the presence of hemoglobin: spectral effect of scattering and absorption on fluorescence

    NASA Astrophysics Data System (ADS)

    Du Le, Vinh Nguyen; Patterson, Michael S.; Farrell, Thomas J.; Hayward, Joseph E.; Fang, Qiyin

    2015-12-01

    The ability to recover the intrinsic fluorescence of biological fluorophores is crucial to accurately identify the fluorophores and quantify their concentrations in the media. Although some studies have successfully retrieved the fluorescence spectral shape of known fluorophores, the techniques usually came with heavy computation costs and did not apply for strongly absorptive media, and the intrinsic fluorescence intensity and fluorophore concentration were not recovered. In this communication, an experimental approach was presented to recover intrinsic fluorescence and concentration of fluorescein in the presence of hemoglobin (Hb). The results indicated that the method was efficient in recovering the intrinsic fluorescence peak and fluorophore concentration with an error of 3% and 10%, respectively. The results also suggested that chromophores with irregular absorption spectra (e.g., Hb) have more profound effects on fluorescence spectral shape than chromophores with monotonic absorption and scattering spectra (e.g., black India ink and polystyrene microspheres).

  14. Experimental recovery of intrinsic fluorescence and fluorophore concentration in the presence of hemoglobin: spectral effect of scattering and absorption on fluorescence.

    PubMed

    Du Le, Vinh Nguyen; Patterson, Michael S; Farrell, Thomas J; Hayward, Joseph E; Fang, Qiyin

    2015-01-01

    The ability to recover the intrinsic fluorescence of biological fluorophores is crucial to accurately identify the fluorophores and quantify their concentrations in the media. Although some studies have successfully retrieved the fluorescence spectral shape of known fluorophores, the techniques usually came with heavy computation costs and did not apply for strongly absorptive media, and the intrinsic fluorescence intensity and fluorophore concentration were not recovered. In this communication, an experimental approach was presented to recover intrinsic fluorescence and concentration of fluorescein in the presence of hemoglobin (Hb). The results indicated that the method was efficient in recovering the intrinsic fluorescence peak and fluorophore concentration with an error of 3% and 10%, respectively. The results also suggested that chromophores with irregular absorption spectra (e.g., Hb) have more profound effects on fluorescence spectral shape than chromophores with monotonic absorption and scattering spectra (e.g., black India ink and polystyrene microspheres).

  15. A cost-effective approach to microporate mammalian cells with the Neon Transfection System.

    PubMed

    Brees, Chantal; Fransen, Marc

    2014-12-01

    Electroporation is one of the most efficient nonviral methods for transferring exogenous DNA into mammalian cells. However, the relatively high costs of electroporation kits and reagents temper the routine use of this fast and easy to perform technique in many laboratories. Several years ago, a new flexible and easy to operate electroporation device was launched under the name Neon Transfection System. This device uses specialized pipette tips containing gold-plated electrodes as electroporation chamber. Here we report a protocol to regenerate these expensive tips as well as some other Neon kit accessories, thereby reducing the cost of electroporation at least 10-fold.

  16. Synthesis of “clickable” acylhomoserine lactone quorum sensing probes: unanticipated effects on mammalian cell activation

    PubMed Central

    Garner, Amanda L.; Yu, Jing; Struss, Anjali Kumari; Lowery, Colin A.; Zhu, Jie; Kim, Sook Kyung; Park, Junguk; Mayorov, Alexander V.; Kaufmann, Gunnar F.; Kravchenko, Vladimir V.; Janda, Kim D.

    2010-01-01

    Alkynyl- and azido-tagged 3-oxo-C12-acylhomoserine lactone probes have been synthesized to examine their potential utility as probes for discovering the mammalian protein target of the Pseudomonas aeruginosa autoinducer, 3-oxo-C12-acylhomoserine lactone. Although such substitutions are commonly believed to be quite conservative, from these studies, we have uncovered a drastic difference in activity between the alkynyl- and azido-modified compounds, and provide an example where such structural modification has proved to be much less than conservative. PMID:21190852

  17. Effect of vitreoscilla hemoglobin and culture conditions on production of bacterial L-asparaginase, an oncolytic enzyme.

    PubMed

    Erenler, Sebnem O; Geckil, Hikmet

    2014-08-01

    L-asparaginase is a widely used cancer chemotherapy enzyme. The source for the enzyme with this property is mainly bacterial and its synthesis is strongly regulated by oxygen. In this study, we utilized two recombinant systems: one carried the gene (vgb) for the Vitreoscilla hemoglobin (VHb), a protein of prokaryotic origin which confers a highly efficient oxygen uptake to its host and the other carried the L-asparaginase gene (ansB). The host bacteria were Escherichia coli, Enterobacter aerogenes, and Pseudomonas aeruginosa. Of these three bacteria, all gram-negative, E. coli and its recombinant strain showed up to sevenfold higher L-asparaginase activity in lactose than in other carbon sources. Although, in this bacterium glycerol was the poorest source for L-asparaginase synthesis, it supported the highest biomass production. In glucose medium, L-asparaginase activity of E. aerogenes was about threefold higher than its vgb and ansB recombinants. ansB recombinant showed significantly higher enzyme levels than both host and vgb recombinants in glycerol and lactose media. In this bacterium, VHb/vgb clearly caused a decrease in the enzyme synthesis under all conditions. As seen for E. aerogens, glycerol was the most favorable carbon source for P. aeruginosa and its vgb strain in terms of both L-asparaginase synthesis and biomass production. The cultures grown in glycerol had more than two- and threefold biomass than in glucose and lactose, respectively, and up to elevenfold than in mannitol. Indeed, the highest biomass production for all bacteria and their recombinants was in glycerol. The VHb/vgb system is clearly advantageous for production of L-asparaginase in P. aeruginosa. The same, however, does not hold true for E. aerogenes.

  18. Mammalian development in space

    NASA Technical Reports Server (NTRS)

    Ronca, April E.

    2003-01-01

    Life on Earth, and thus the reproductive and ontogenetic processes of all extant species and their ancestors, evolved under the constant influence of the Earth's l g gravitational field. These considerations raise important questions about the ability of mammals to reproduce and develop in space. In this chapter, I review the current state of our knowledge of spaceflight effects on developing mammals. Recent studies are revealing the first insights into how the space environment affects critical phases of mammalian reproduction and development, viz., those events surrounding fertilization, embryogenesis, pregnancy, birth, postnatal maturation and parental care. This review emphasizes fetal and early postnatal life, the developmental epochs for which the greatest amounts of mammalian spaceflight data have been amassed. The maternal-offspring system, the coordinated aggregate of mother and young comprising mammalian development, is of primary importance during these early, formative developmental phases. The existing research supports the view that biologically meaningful interactions between mothers and offspring are changed in the weightlessness of space. These changes may, in turn, cloud interpretations of spaceflight effects on developing offspring. Whereas studies of mid-pregnant rats in space have been extraordinarily successful, studies of young rat litters launched at 9 days of postnatal age or earlier, have been encumbered with problems related to the design of in-flight caging and compromised maternal-offspring interactions. Possibilities for mammalian birth in space, an event that has not yet transpired, are considered. In the aggregate, the results indicate a strong need for new studies of mammalian reproduction and development in space. Habitat development and systematic ground-based testing are important prerequisites to future research with young postnatal rodents in space. Together, the findings support the view that the environment within which young

  19. Mammalian development in space.

    PubMed

    Ronca, April E

    2003-01-01

    Life on Earth, and thus the reproductive and ontogenetic processes of all extant species and their ancestors, evolved under the constant influence of the Earth's l g gravitational field. These considerations raise important questions about the ability of mammals to reproduce and develop in space. In this chapter, I review the current state of our knowledge of spaceflight effects on developing mammals. Recent studies are revealing the first insights into how the space environment affects critical phases of mammalian reproduction and development, viz., those events surrounding fertilization, embryogenesis, pregnancy, birth, postnatal maturation and parental care. This review emphasizes fetal and early postnatal life, the developmental epochs for which the greatest amounts of mammalian spaceflight data have been amassed. The maternal-offspring system, the coordinated aggregate of mother and young comprising mammalian development, is of primary importance during these early, formative developmental phases. The existing research supports the view that biologically meaningful interactions between mothers and offspring are changed in the weightlessness of space. These changes may, in turn, cloud interpretations of spaceflight effects on developing offspring. Whereas studies of mid-pregnant rats in space have been extraordinarily successful, studies of young rat litters launched at 9 days of postnatal age or earlier, have been encumbered with problems related to the design of in-flight caging and compromised maternal-offspring interactions. Possibilities for mammalian birth in space, an event that has not yet transpired, are considered. In the aggregate, the results indicate a strong need for new studies of mammalian reproduction and development in space. Habitat development and systematic ground-based testing are important prerequisites to future research with young postnatal rodents in space. Together, the findings support the view that the environment within which young

  20. Effects of track structure and cell inactivation on the calculation of heavy ion mutation rates in mammalian cells

    NASA Technical Reports Server (NTRS)

    Cucinotta, F. A.; Wilson, J. W.; Shavers, M. R.; Katz, R.

    1996-01-01

    It has long been suggested that inactivation severely effects the probability of mutation by heavy ions in mammalian cells. Heavy ions have observed cross sections of inactivation that approach and sometimes exceed the geometric size of the cell nucleus in mammalian cells. In the track structure model of Katz the inactivation cross section is found by summing an inactivation probability over all impact parameters from the ion to the sensitive sites within the cell nucleus. The inactivation probability is evaluated using the dose-response of the system to gamma-rays and the radial dose of the ions and may be equal to unity at small impact parameters for some ions. We show how the effects of inactivation may be taken into account in the evaluation of the mutation cross sections from heavy ions in the track structure model through correlation of sites for gene mutation and cell inactivation. The model is fit to available data for HPRT mutations in Chinese hamster cells and good agreement is found. The resulting calculations qualitatively show that mutation cross sections for heavy ions display minima at velocities where inactivation cross sections display maxima. Also, calculations show the high probability of mutation by relativistic heavy ions due to the radial extension of ions track from delta-rays in agreement with the microlesion concept. The effects of inactivation on mutations rates make it very unlikely that a single parameter such as LET or Z*2/beta(2) can be used to specify radiation quality for heavy ion bombardment.

  1. The effect of silver nanoparticles and silver ions on mammalian and plant cells in vitro.

    PubMed

    Jiravova, Jana; Tomankova, Katerina Barton; Harvanova, Monika; Malina, Lukas; Malohlava, Jakub; Luhova, Lenka; Panacek, Ales; Manisova, Barbora; Kolarova, Hana

    2016-10-01

    Silver nanoparticles (AgNPs) are the most frequently applied nanomaterials. In our experiments, we tested AgNPs (size 27 nm) manufactured by the Tollens process. Physico-chemical methods (TEM, DLS, AFM and spectrophotometry) were used for characterization and imaging of AgNPs. The effects of AgNPs and Ag(+) were studied in two experimental models (plant and mammalian cells). Human keratinocytes (SVK14) and mouse fibroblasts (NIH3T3) cell lines were selected to evaluate the cytotoxicity and genotoxicity effect on mammalian cells. Higher sensitivity to AgNPs and Ag(+) was observed in NIH3T3 than in SVK14 cells. AgNPs accumulated in the nucleus of NIH3T3 cells, caused DNA damage and increased the number of apoptotic and necrotic cells. Three genotypes of Solanum spp. (S. lycopersicum cv. Amateur, S. chmielewskii, S. habrochaites) were selected to test the toxicity of AgNPs and Ag(+) on the plant cells. The highest values of peroxidase activity and lipid peroxidation were recorded after the treatment of S. habrochaites genotype with AgNPs. Increased ROS levels were likely the reason for observed damaged membranes in S. habrochaites. We found that the cytotoxic and genotoxic effects of AgNPs depend not only on the characteristics of nanoparticles, but also on the type of cells that are treated with AgNPs.

  2. Propofol Enhances Hemoglobin-Induced Cytotoxicity in Neurons

    PubMed Central

    Yuan, Jing; Cui, Guiyun; Li, Wenlu; Zhang, Xiaoli; Wang, Xiaoying; Zheng, Hui; Zhang, Jian; Xiang, Shuanglin; Xie, Zhongcong

    2016-01-01

    BACKGROUND It has been increasingly suggested that propofol protects against hypoxic-/ischemic-induced neuronal injury. As evidenced by hemorrhage-induced stroke, hemorrhage into the brain may also cause brain damage. Whether propofol protects against hemorrhage-induced brain damage remains unknown. Therefore, in this study, we investigated the effects of propofol on hemoglobin-induced cytotoxicity in cultured mouse cortical neurons. METHODS Neurons were prepared from the cortex of embryonic 15-day-old mice. Hemoglobin was used to induce cytotoxicity in the neurons. The neurons were then treated with propofol for 4 hours. Cytotoxicity was determined by lactate dehydrogenase release assay. Caspase-3 activation was examined by Western blot analysis. Finally, the free radical scavenger U83836E was used to examine the potential involvement of oxidative stress in propofol’s effects on hemoglobin-induced cytotoxicity. RESULTS We found that treatment with hemoglobin induced cytotoxicity in the neurons. Propofol enhanced hemoglobin-induced cytotoxicity. Specifically, there was a significant difference in the amount of lactate dehydrogenase release between hemoglobin plus saline (19.84% ± 5.38%) and hemoglobin plus propofol (35.79% ± 4.41%) in mouse cortical neurons (P = 0.00058, Wilcoxon Mann-Whitney U test, n = 8 in the control group or the treatment group). U83836E did not attenuate the enhancing effects of propofol on hemoglobin-induced cytotoxicity in the neurons, and propofol did not significantly affect caspase-3 activation induced by hemoglobin. These data suggested that caspase-3 activation and oxidative stress might not be the underlying mechanisms by which propofol enhanced hemoglobin-induced cytotoxicity. Moreover, these data suggested that the neuroprotective effects of propofol would be dependent on the condition of the brain injury, which will need to be confirmed in future studies. CONCLUSIONS These results from our current proof-of-concept study should

  3. Study of the Effects of Ultrasonic Waves on the Reproductive Integrity of Mammalian Cells Cultured in Vitro

    NASA Technical Reports Server (NTRS)

    Martins, B. I.

    1971-01-01

    The effects of monochromatic ultrasonic waves of 0.1, 0.5, 1.0, 2.0 and, 3.3 MHz frequency on the colony-forming ability of mammalian cells (M3-1,V79, Chang's and T-1) cultured in vitro have been studied to determine the nature of the action of ultrasonic energy on biological systems at the cellular level. The combined effect of ultrasound and X-rays has also been studied. It is concluded: (1) Ultrasonic irradiation causes both lethal and sublethal damage. (2) There is a threshold dose rate for lethal effects. (3) The effectiveness of ultrasonic waves in causing cell death probably depends on the frequency and the amplitude of the waves for a given cell line, indicating a possible resonance phenomenon.

  4. Activation of mammalian target of rapamycin signaling in skeletal muscle of neonatal chicks: effects of dietary leucine and age.

    PubMed

    Deng, Huiling; Zheng, Aijuan; Liu, Guohua; Chang, Wenhuan; Zhang, Shu; Cai, Huiyi

    2014-01-01

    The mammalian target of rapamycin (mTOR) signaling pathway is necessary for cellular protein synthesis regulation. Leucine was reported to stimulate muscle protein synthesis in mammalian embryos and neonates, but in higher animals (chickens) the effect of dietary leucine on mTOR signaling is unknown. Thus, we investigated the effects of dietary leucine and age on mRNA expression and phosphorylation of mTOR as well as its downstream targets, ribosomal protein S6 kinase (S6K1) and eukaryotic initiation factor 4E binding protein 1 (4E-BP1) in chick pectoral muscles. One hundred eighty newly hatched male chicks were randomly assigned to 1 of 3 dietary leucine treatment groups (1.43, 1.73, and 2.03% leucine) for 14 d, respectively. Each treatment group consisted of 6 cages with 10 chicks each. On d 3, 7, and 14, plasma insulin and leucine were measured and target gene expression and phosphorylation was assessed. Dietary leucine influenced plasma leucine but not insulin, and plasma leucine and insulin declined with chick age. The mTOR, S6K1, and 4E-BP1 mRNA expression and phosphorylation within chick pectoral muscles were upregulated with increased dietary leucine but downregulated with increased chick age. Thus, high dietary leucine activates target of rapamycin signaling pathways in skeletal muscle of neonatal chicks to stimulate muscle protein synthesis, and this pathway is attenuated with aging.

  5. Studies on the effects of microgravity on the ultrastructure and functions of cultured mammalian cells (L-6)

    NASA Technical Reports Server (NTRS)

    Sato, Atsushige

    1993-01-01

    The human body consists of 10(exp 13) cells. Understanding the mechanisms by which the cells sense and respond to microgravity is very important as the basis for space biology. The cells were originally isolated aseptically from mammalian bodies and cultured in vitro. A set of cell culture vessels was developed to be applied to three kinds of space flight experiments. Experiment 1 is to practice the cell culture technique in a space laboratory and obtain favorable growth of the cells. Aseptic handling in tryspin treatment and medium renewal will be tested. The cells, following space flight, will be returned to the ground and cultured continuously to investigate the effects of space flight on the cellular characteristics. Experiment 2 is to examine the cytoskeletal structure of the cells under microgravity conditions. The cytoskeletal structure plays essential roles in the morphological construction, movements, axonal transport, and differentiation of the cells. The cells fixed during space flight will be returned and the cytoskeleton and ultrastructure observed using electron microscopy and fluorescence microscopy. Experiment 3 is to study the cellular productivity of valuable substances. The waste medium harvested during space flight are returned and quantitated for the cellular products. The effects of microgravity on mammalian cells will be clarified from the various aspects.

  6. Analysis of bicarbonate binding to crocodilian hemoglobin.

    PubMed

    Bauer, C; Forster, M; Gros, G; Mosca, A; Perrella, M; Rollema, H S; Vogel, D

    1981-08-25

    Crocodilian hemoglobin has a high intrinsic oxygen affinity but does not react with those organic phosphate esters that normally control the oxygen affinity of blood in higher vertebrates. Instead, its oxygen affinity is greatly lowered by CO2. The present study was undertaken to determine the nature of the CO2 binding to the hemoglobin of a crocodilian species, the Caiman, both qualitatively and quantitatively. The following parameters were measured: (a) carbamino compounds of deoxy- and oxyhemoglobin, (b) the effect of CO2 (at constant pH) on the oxygen affinity of Caiman hemoglobin, (c) total CO2 concentration of hemoglobin solutions at different pH and pCO2 values, and (d) the effect of CO2 on CD spectra of Caiman aquomethemoglobin. An analysis of the results of these measurements revealed that CO2 binding in the form of carbamate was not oxygen-linked and cannot, therefore, mediate the CO2 effect on the oxygen affinity. It was found, however, that 2 mol of bicarbonate can be bound/hemoglobin tetramer and that the association constant of the bicarbonate anion greatly depends upon the state of ligation. At pH 7.02 and 25 degrees C, a numerical value of 2.0 X 10(3) M-1 was obtained for deoxyhemoglobin, while for oxyhemoglobin no significant bicarbonate binding could be observed. At more alkaline pH (pH greater than or equal to 7.5), the association constant for deoxyhemoglobin decreases. Circular dichroism of Caiman aquomethemoglobin decreased considerably in the 287-nm region upon addition of CO2 at constant pH, an effect very similar to the one caused by inositol hexaphosphate in human aquomethemoglobin.

  7. THE RENAL HANDLING OF HEMOGLOBIN

    PubMed Central

    Bunn, H. Franklin; Jandl, James H.

    1969-01-01

    The fate of small doses of isotopically labeled isologous hemoglobin was studied in the rat. When haptoglobin depleted animals were given 2.0 mg of 59Fe hemoglobin intravenously, nearly half was trapped by the kidneys. Kidney 59Fe activity disappeared slowly over several weeks. Whatever iron was lost from the kidneys was largely reutilized. In contrast, the porphyrin of hemoglobin absorbed by the kidneys appeared to be rapidly catabolized, since 5 hr after the injection of 14C or 59Fe heme-labeled hemoglobin only a small fraction was recovered as hematin. Likewise, after injection of globin-labeled hemoglobin, rapid disappearance of kidney protein activity indicated that the absorbed globin was readily catabolized in situ. PMID:5778790

  8. Effect of substrate storage conditions on the stability of "Smart" films used for mammalian cell applications

    NASA Astrophysics Data System (ADS)

    Bluestein, Blake M.; Reed, Jamie A.; Canavan, Heather E.

    2017-01-01

    When poly(N-isopropyl acrylamide) (pNIPAM) is tethered to a surface, it can induce the spontaneous release of a sheet of mammalian cells. The release of cells is a result of the reversible phase transition the polymer undergoes at its lower critical solution temperature (LCST). Many techniques are used for the deposition of pNIPAM onto cell culture substrates. Previously, we compared two methods of deposition (plasma polymerization, and co-deposition with a sol-gel). We proved that although both were technically appropriate for obtaining thermoresponsive pNIPAM films, the surfaces that were co-deposited with a sol-gel caused some disruption in cell activity. The variation of cell behavior could be due to the delamination of pNIPAM films leaching toxic chemicals into solution. In this work, we assessed the stability of these pNIPAM films by manipulating the storage conditions and analyzing the surface chemistry using X-ray photoelectron spectroscopy (XPS) and contact angle measurements over the amount of time required to obtain confluent cell sheets. From XPS, we demonstrated that ppNIPAM (plasma polymerized NIPAM) films remains stable across all storage conditions while sol-gel deposition show large deviations after 48 h of storage. Cell response of the deposited films was assessed by investigating the cytotoxicity and biocompatibility. The 37 °C and high humidity storage affects sol-gel deposited films, inhibiting normal cell growth and proper thermoresponse of the film. Surface chemistry, thermoresponse and cell growth remained similar for all ppNIPAM surfaces, indicating these substrates are more appropriate for mammalian cell culture applications.

  9. Induction of Hemoglobin Accumulation in Human K562 Cells by Hemin is Reversible

    NASA Astrophysics Data System (ADS)

    Dean, Ann; Erard, Francois; Schneider, Arthur B.; Schechter, Alan N.

    1981-04-01

    Twenty micromolar hemin causes no change in the rate of division of K562 cells but results in accumulation of 11 to 14 picograms of embryonic and fetal hemoglobins per cell. This effect is reversible, and hemoglobin induction in response to hemin, and loss of hemoglobin upon removal of hemin, can be cyclically repeated. The cells can be indefinitely subcultured in the presence of the inducer. Thus, the control of hemoglobin levels in K562 cells does not depend on irreversible differentiation.

  10. Respiration of mammalian cells at low concentrations of oxygen: I. Effect of hypoxic-cell radiosensitizing drugs.

    PubMed Central

    Koch, C. J.; Biaglow, J. E.

    1978-01-01

    Drugs which sensitize hypoxic mammalian cells to radiation damage in vitro can also affect the cellular respiration rate. This phenomenon was studied in detail to determine whether the changes in oxygen consumption occur at low oxygen concentrations and under optimal nutritional conditions. We have found that cells in tissue culture can undergo adaptive changes in respiration (electron flow) which make them insensitive to the effects of radiosensitizing drugs and even respiration uncouplers such as dinitrophenol, and the inhibitors rotenone and cyanide. At low cell densities, where nutrient depletion in the medium would be negligible, the drugs have reduced effects, particularly at low oxygen concentrations (below 40 mmHg oxygen partial pressure). Parallel cytotoxicity and growht inhibition studies indicate that most drugs are unlikely to have substantial effect on respiration at non-cytotoxic levels. PMID:277219

  11. Comparative study of the effect of BPA and its selected analogues on hemoglobin oxidation, morphological alterations and hemolytic changes in human erythrocytes.

    PubMed

    Maćczak, Aneta; Bukowska, Bożena; Michałowicz, Jaromir

    2015-01-01

    Bisphenol A (BPA) has been shown to provoke many deleterious impacts on human health, and thus it is now successively substituted by BPA analogues, whose effects have been poorly investigated. Up to now, only one study has been realized to assess the effect of BPA on human erythrocytes, which showed its significant hemolytic and oxidative potential. Moreover, no study has been conducted to evaluate the effect of BPA analogues on red blood cells. The purpose of the present study was to compare the impact of BPA and its selected analogues such as bisphenol F (BPF), bisphenol S (BPS) and bisphenol AF (BPAF) on hemolytic and morphological changes and hemoglobin oxidation (methemoglobin formation) of human erythrocytes. The erythrocytes were incubated with different bisphenols concentrations ranging from 0.5 to 500μg/ml for 1, 4 and 24h. The compounds examined caused hemolysis in human erythrocytes with BPAF exhibiting the strongest effect. All bisphenols examined caused methemoglobin formation with BPA inducing the strongest oxidative potential. Flow cytometry analysis showed that all bisphenols (excluding BPS) induced significant changes in erythrocytes size. Changes in red blood cells shape were conducted using phase contrast microscopy. It was noticed that BPA and BPAF induced echinocytosis, BPF caused stomatocytosis, while BPS did not provoke significant changes in shape of red blood cells. Generally, the results showed that BPS, which is the main substituent of bisphenol A in polymers and thermal paper production, exhibited significantly lower disturbance of erythrocyte functions than BPA.

  12. Carrion fly-derived DNA as a tool for comprehensive and cost-effective assessment of mammalian biodiversity.

    PubMed

    Calvignac-Spencer, Sébastien; Merkel, Kevin; Kutzner, Nadine; Kühl, Hjalmar; Boesch, Christophe; Kappeler, Peter M; Metzger, Sonja; Schubert, Grit; Leendertz, Fabian H

    2013-02-01

    Large-scale monitoring schemes are essential in assessing global mammalian biodiversity, and in this framework, leeches have recently been promoted as an indirect source of DNA from terrestrial mammal species. Carrion feeding flies are ubiquitous and can be expected to feed on many vertebrate carcasses. Hence, we tested whether fly-derived DNA analysis may also serve as a novel tool for mammalian diversity surveys. We screened DNA extracted from 201 carrion flies collected in tropical habitats of Côte d'Ivoire and Madagascar for mammal DNA using multiple PCR systems and retrieved DNA sequences from a diverse set of species (22 in Côte d'Ivoire, four in Madagascar) exploiting distinct forest strata and displaying a broad range of body sizes. Deep sequencing of amplicons generated from pools of flies performed equally well as individual sequencing approaches. We conclude that the analysis of fly-derived DNA can be implemented in a very rapid and cost-effective manner and will give a relatively unbiased picture of local mammal diversity. Carrion flies therefore represent an extraordinary and thus far unexploited resource of mammal DNA, which will probably prove useful for future inventories of wild mammal communities.

  13. High-fat diet-induced met-hemoglobin formation in rats prone (WOKW) or resistant (DA) to the metabolic syndrome: effect of CoQ10 supplementation.

    PubMed

    Orlando, Patrick; Silvestri, Sonia; Brugè, Francesca; Tiano, Luca; Kloting, Ingrid; Falcioni, Giancarlo; Polidori, Carlo

    2014-01-01

    The aim of this study was to evaluate the effects of a high-fat diet (HFD) on oxidative indexes in WistarOttawaKarlsburg W (WOKW) rats used as a model of metabolic syndrome in comparison with Dark Agouti (DA) rats used as a control strain. This syndrome is defined by the occurrence of two or more risk factors including obesity, hypertension, dyslipidemia, and insulin resistance. Forty rats were used in the study and the effect of HFD was evaluated in terms of body weight and both hemoglobin and CoQ oxidative status. Moreover, 16 rats (8 of each strain) were supplemented with 3 mg/100 g b.w. of CoQ10 for 1 month in view of its beneficial properties in cardiovascular disease due to its antioxidant activity in the lipid environment. HFD promoted an increase in body weight, in particular in WOKW males, and in the methemoglobin (met-Hb) index in both strains. Moreover, HFD promoted endogenous CoQ10 oxidation. CoQ10 supplementation was able to efficiently counteract the HFD pro-oxidant effects, preventing met-Hb formation and CoQ oxidation.

  14. Ethylene oxide inhalation at different exposure-rates affects binding levels in mouse germ cells and hemoglobin. Possible explanation for the effect.

    PubMed

    Sega, G A; Brimer, P A; Generoso, E E

    1991-08-01

    Male mice were exposed to [3H]EtO by inhalation at different exposure rates (300 parts per million (ppm) of EtO for 1 h: 150 ppm for 2 h: 75 ppm for 4 h). The total exposure was fixed at 300 ppm-h. The amount of EtO binding to developing spermatogenic stages, to sperm DNA, to testis DNA and to hemoglobin was then measured as a function of the EtO exposure rate. Generally, as the exposure rate increased there was an increase in the amount of EtO binding to the targets. For example, alkylation of sperm from the caudal epididymides 6 d posttreatment, of DNA from the vas sperm (averaged over 4 time points), of testis DNA (90 min posttreatment), and of hemoglobin (averaged over 4 time points), was 2.0 +/- 0.2 (SD), 1.8 +/- 0.4, 2.9 +/- 0.3, and 1.5 +/- 0.1 times greater, respectively, after an exposure to 300 ppm for 1 h than after an exposure to 75 ppm for 4 h. The testicular DNA from animals exposed to 300 ppm of [3H]EtO for 1 h was also analyzed for the presence of N7-hydroxyethylguanine (N7HEG) and O6-hydroxyethylguanine (O6HEG). The half-life (T1 2) of the N7HEG in the testis DNA was calculated to be 2.8 d. This lesion was removed relatively rapidly from the testis DNA and was probably excised by enzymatic repair. No formation of O6HEG was detected in any of the testis DNA samples analyzed. Additional experiments showed that the exposure rate effect was the result of less total EtO being taken in by the mice over long exposure times compared to that taken in during shorter exposure times at higher concentrations. This result argues against the idea that the exposure rate effect is the result of physiological/enzymological changes affecting transport or metabolism of the chemical within the animals under different exposure rate conditions.

  15. Non-invasive hemoglobin monitoring.

    PubMed

    Joseph, Bellal; Haider, Ansab; Rhee, Peter

    2016-09-01

    Technology has transformed the practice of medicine and surgery in particular over the last several decades. This change in practice has allowed diagnostic and therapeutic tests to be performed less invasively. Hemoglobin monitoring remains one of the most commonly performed diagnostic tests in the United States. Recently, non-invasive hemoglobin monitoring technology has gained popularity. The aim of this article is to review the principles of how this technology works, pros and cons, and the implications of non-invasive hemoglobin technology particularly in trauma surgery.

  16. Thermostability of mammalian brain ribosomes and the effects of nucleoside triphosphates on their heat-sensitivity.

    PubMed

    Grove, B K; Johnson, T C; Gilbert, B E

    1974-02-01

    Mammalian brain ribosomes were found to be heat-labile. On preincubation of the ribosomes at 37 degrees C, their ability to participate in polypeptide-synthesis reactions was substantially diminished. Despite the sensitivity of ribosomal protein synthesis to heat-inactivation, preincubation resulted in no significant alterations in ribosomal sedimentation profiles or changes in the integrity of the ribosomal RNA. The thermolability of brain ribosomes was shown to be associated with their inability to bind both template RNA and aminoacyl-tRNA. Similar experiments with brain ribosomal subunits demonstrated that the small (40S) subunit was more sensitive to heat-inactivation than the large (60S) subunit. The presence of ATP (1mm) protected ribosomes from thermal inactivation, although this protection was shown to be temporary. The protection appeared to be specific to nucleoside triphosphates, since GTP and UTP also stabilized ribosomes to thermal denaturation whereas nucleoside diphosphates (ADP) and nucleoside monophosphates (AMP and cyclic AMP) did not alter ribosomal sensitivity to heat. Although 1mm concentrations of nucleoside triphosphates protected ribosomes from heat-inactivation, the presence of higher concentrations resulted in complete inactivation of ribosomal activity.

  17. Effect of extracellular osmolality on cell volume and resting metabolism in mammalian skeletal muscle.

    PubMed

    Antolic, AnaMaria; Harrison, Rosemarie; Farlinger, Chris; Cermak, Naomi M; Peters, Sandra J; LeBlanc, Paul; Roy, Brian D

    2007-05-01

    The purpose of the present investigation was to establish an in vitro mammalian skeletal muscle model to study acute alterations in resting skeletal muscle cell volume. Isolated, whole muscles [soleus and extensor digitorum longus (EDL)] were dissected from Long-Evans rats and incubated for 60 min in Sigma medium 199 (1 g of resting tension, bubbled with 95% O(2)-5% O(2), 30 +/- 2 degrees C, and pH 7.4). Medium osmolality was altered to simulate hyposmotic (190 +/- 10 mmol/kg) or hyperosmotic conditions (400 +/- 10 mmol/kg), whereas an isosmotic condition (290 +/- 10 mmol/kg) served as a control. After incubation, relative water content of the muscle decreased with hyperosmotic and increased with hyposmotic condition in both muscle types (P < 0.05). The cross-sectional area of soleus type I and type II fibers increased (P < 0.05) in hyposmotic, whereas hyperosmotic exposure led to no detectable changes. The EDL type II fiber area decreased in the hyperosmotic condition and increased after hyposmotic exposure, whereas no change was observed in EDL type I fibers. Furthermore, exposure to the hyperosmotic condition in both muscle types resulted in decreased muscle ATP and phosphocreatine (P < 0.05) contents and increased creatine and lactate contents (P < 0.05) compared with control and hyposmotic conditions. This isolated skeletal muscle model proved viable and demonstrated that altering extracellular osmolality could cause acute alterations in muscle water content and resting muscle metabolism.

  18. Metabolic rate limits the effect of sperm competition on mammalian spermatogenesis.

    PubMed

    delBarco-Trillo, Javier; Tourmente, Maximiliano; Roldan, Eduardo R S

    2013-01-01

    Sperm competition leads to increased sperm production in many taxa. This response may result from increases in testes size, changes in testicular architecture or changes in the kinetics of spermatogenesis, but the impact of each one of these processes on sperm production has not been studied in an integrated manner. Furthermore, such response may be limited in species with low mass-specific metabolic rate (MSMR), i.e., large-bodied species, because they cannot process energy and resources efficiently enough both at the organismic and cellular levels. Here we compare 99 mammalian species and show that higher levels of sperm competition correlated with a) higher proportions of seminiferous tubules, b) shorter seminiferous epithelium cycle lengths (SECL) which reduce the time required to produce sperm, and c) higher efficiencies of Sertoli cells (involved in sperm maturation). These responses to sperm competition, in turn, result in higher daily sperm production, more sperm stored in the epididymides, and more sperm in the ejaculate. However, the two processes that require processing resources at faster rates (SECL and efficiency of Sertoli cells) only respond to sperm competition in species with high MSMR. Thus, increases in sperm production with intense sperm competition occur via a complex network of mechanisms, but some are constrained by MSMR.

  19. The effect of hydroxyurea and trichostatin a on targeted nucleotide exchange in yeast and Mammalian cells.

    PubMed

    Parekh-Olmedo, Hetal; Engstrom, Julia U; Kmiec, Eric B

    2003-12-01

    Targeted nucleotide exchange (TNE) is a process by which a synthetic DNA oligonucleotide, partially complementary to a site in a chromosomal or an episomal gene directs the reversal of a single nucleotide at a specific site. To protect against nuclease digestion, the oligonucleotide is modified with derivative linkages among the terminal bases. We have termed these molecules modified single-stranded oligonucleotides (MSOs). Current models suggest that the reaction occurs in two steps. The first, DNA pairing, involves the alignment of the MSO with the target site and its assimilation into the target helix forming a D-loop. The second phase centers around the repair of a single base mismatch formed between the MSO and its complementary strand in the D-loop. Nucleotide exchange is promoted in all likelihood by the mismatch repair system. A critical feature of successful TNE is the accessibility of the target site for the MSO and the factors that increase the dynamic nature of the chromatin that will likely increase the frequency. Here, we report that two factors, trichostatin A and hydroxyurea, elevate gene repair of a mutant hygromycin gene in Saccharomyces cerevisiae and a mutant eGFP gene in a mammalian cell line, MCF-10AT1 cells. Trichostatin A (TSA) acts by preventing the deacetylation of histones while hydroxyurea (HU) reduces the rate of replication. Both of these activities, by their very nature, create a more open configuration of the MSO into the target site.

  20. The effects of weightlessness on the human organism and mammalian cells.

    PubMed

    Pietsch, J; Bauer, J; Egli, M; Infanger, M; Wise, P; Ulbrich, C; Grimm, D

    2011-07-01

    It has always been a desire of mankind to conquest Space. A major step in realizing this dream was the completion of the International Space Station (ISS). Living there for several months confirmed early observations of short-term spaceflights that a loss of gravity affects the health of astronauts. Space medicine tries to understand the mechanism of microgravity-induced health problems and to conceive potent countermeasures. There are four different aspects which make space medicine appealing: i) finding better strategies for adapting astronauts to weightlessness; ii) identification of microgravity-induced diseases (e.g. osteoporosis, muscle atrophy, cardiac problems and others); iii) defining new therapies to conquer these diseases which will benefit astronauts as well as people on Earth in the end; and iv) on top of that, unveiling the mechanisms of weightlessness-dependent molecular and cellular changes is a requirement for improving space medicine. In mammalian cells, microgravity induces apoptosis and alters the cytoskeleton and affects signal transduction pathways, cell differentiation, growth, proliferation, migration and adhesion. This review focused on gravi-sensitive signal transduction elements and pathways as well as molecular mechanisms in human cells, aiming to understand the cellular changes in altered gravity. Moreover, the latest information on how these changes lead to clinically relevant health problems and current strategies of countermeasures are reviewed.

  1. Concentration-dependent Effects of Nuclear Lamins on Nuclear Size in Xenopus and Mammalian Cells*

    PubMed Central

    Jevtić, Predrag; Edens, Lisa J.; Li, Xiaoyang; Nguyen, Thang; Chen, Pan; Levy, Daniel L.

    2015-01-01

    A fundamental question in cell biology concerns the regulation of organelle size. While nuclear size is exquisitely controlled in different cell types, inappropriate nuclear enlargement is used to diagnose and stage cancer. Clarifying the functional significance of nuclear size necessitates an understanding of the mechanisms and proteins that control nuclear size. One structural component implicated in the regulation of nuclear morphology is the nuclear lamina, a meshwork of intermediate lamin filaments that lines the inner nuclear membrane. However, there has not been a systematic investigation of how the level and type of lamin expression influences nuclear size, in part due to difficulties in precisely controlling lamin expression levels in vivo. In this study, we circumvent this limitation by studying nuclei in Xenopus laevis egg and embryo extracts, open biochemical systems that allow for precise manipulation of lamin levels by the addition of recombinant proteins. We find that nuclear growth and size are sensitive to the levels of nuclear lamins, with low and high concentrations increasing and decreasing nuclear size, respectively. Interestingly, each type of lamin that we tested (lamins B1, B2, B3, and A) similarly affected nuclear size whether added alone or in combination, suggesting that total lamin concentration, and not lamin type, is more critical to determining nuclear size. Furthermore, we show that altering lamin levels in vivo, both in Xenopus embryos and mammalian tissue culture cells, also impacts nuclear size. These results have implications for normal development and carcinogenesis where both nuclear size and lamin expression levels change. PMID:26429910

  2. Comparative study on thiol drugs' effect on tert-butyl hydroperoxide induced luminol chemiluminescence in human erythrocyte lysate and hemoglobin oxidation.

    PubMed

    Sajewicz, Waldemar; Zalewska, Marta; Milnerowicz, Halina

    2015-02-01

    The current studies have investigated the effect of heterocyclic drugs with the single thiol group (thiamazole, mercaptopurine) and dithiol aliphatic drugs (dimercaptosuccinic acid, dithiothreitol) under oxidative stress conditions, using tert-butyl hydroperoxide (t-BuOOH), in human erythrocyte lysate with the luminol-enhanced chemiluminescence technique. Knowing that oxidative processes induced by t-BuOOH are triggered by (oxy)hemoglobin (Hb), the effect of different thiol drugs (RSH) on isolated human Hb oxidation to methemoglobin (MHb) and hemichromes (HChr) was further considered. Three types of chemiluminescence curves, fitting to logistic-exponential model, have been revealed under influence of RSH. Structure of the data (MHb and HChr production, and free radical activity of RSH) in Principal Component Analysis visualization and kinetic profiles of chemiluminescence integrate information in terms of the diversity of RSH reaction mechanisms depending on the specific molecular context of the given thiol: aliphatic or aromatic nature as well as the number and position of the -SH groups in the molecule. The study conducted in presented in vitro systems indicates the potential role of thiol drugs mediated toxicity in an oxidative stress dependent mechanism.

  3. Effect of hemoglobin on the uptake of /sup 3/H-norepinephrine and /sup 3/H-choline chloride into porcine cerebral arteries

    SciTech Connect

    Linnik, M.D.; Lee, T.J.F.

    1986-03-01

    Prolonged constriction of cerebral arteries often follows subarachnoid hemorrhage (SAH). SAH exposes hemoglobin (Hb) to cerebral arteries and Hb has been demonstrated to induce vasoconstriction as well as alter cerebrovascular neurogenic response characteristics. The effect of Hb on uptake of /sup 3/H-norepinephrine (/sup 3/H-NE) and /sup 3/H-choline chloride (/sup 3/H-ChCl) into porcine cerebral arteries was therefore examined. 0.5 to 50 ..mu..M porcine Hb caused a dose-dependent inhibition of /sup 3/H-NE uptake into the anterior (ANT), internal carotid (IC) and middle cerebral (MC) arteries of the pig. IC/sub 50/ values for uptake inhibition were: ANT, 31 ..mu..M; IC, 34 ..mu..M; MC, 37 ..mu..M. Porcine serum albumin (PSA) in the same concentration range also caused a decrease in /sup 3/H-NE uptake. An examination of protein-ligand interactions using column chromatography demonstrated binding of /sup 3/H-NE by both Hb and PSA. This protein binding may be responsible for part of the uptake inhibition. Hb and PSA had little effect on /sup 3/H-ChCl uptake into these arteries.

  4. Error in noninvasive spectrophotometric measurement of blood hemoglobin concentration under conditions of blood loss.

    PubMed

    Naftalovich, Rotem; Naftalovich, Daniel

    2011-10-01

    SpHb to macro hemoglobin concentrations during blood loss due to the increasing effect of microcirculatory hemoglobin measurement on the mixed parameter, SpHb.

  5. Weak binding gases as modulators of hemoglobin function

    SciTech Connect

    Schoenborn, B P; Saxena, A; North, B E

    1980-01-01

    Studies are reported in which the mechanisms of binding of inert gaseous agents to hemoglobin and myoglobin are investigated. Specific binding sites are mapped. Possible effects on sickle cell formation and oxygen binding are discussed. (ACR)

  6. The effect of space microgravity on the physiological activity of mammalian resident cardiac stem cells

    NASA Astrophysics Data System (ADS)

    Belostotskaya, Galina; Zakharov, Eugeny

    Prolonged exposure to weightlessness during space flights is known to cause depression of heart function in mammals. The decrease in heart weight and its remodeling under the influence of prolonged weightlessness (or space microgravity) is assumed to be due to both morphological changes of working cardiomyocytes and their progressive loss, as well as to possible depletion of resident cardiac stem cells (CSCs) population, or their inability to self-renewal and regeneration of muscle tissue under conditions of weightlessness. We have previously shown that the presence of different maturity clones formed by resident CSCs not only in culture but also in the mammalian myocardium can be used as an indicator of the regenerative activity of myocardial cells [Belostotskaya, et al., 2013: 2014]. In this study, we were interested to investigate whether the 30-day near-Earth space flight on the spacecraft BION-M1 affects the regenerative potential of resident CSCs. Immediately after landing of the spacecraft, we had examined the presence of resident c-kit+, Sca-1+ and Isl1+ CSCs and their development in suspension of freshly isolated myocardial cells of C57BL mice in comparison to controls. Cardiac cell suspension was obtained by enzymatic digestion of the heart [Belostotskaya and Golovanova, 2014]. Immunocytochemically stained preparations of fixed cells were analyzed with confocal microscope Leica TCS SP5 (Germany) in the Resource Center of St-Petersburg State University. CSCs were labeled with appropriate antibodies. CSCs differentiation into mature cardiomyocytes was verified using antibodies to Sarcomeric α-Actinin and Cardiac Troponin T. Antibodies to Connexin43 were used to detect cell-cell contacts. All antibodies were conjugated with Alexa fluorochromes (488, 532, 546, 568, 594 and/or 647 nm), according to Zenon-technology (Invitrogen). It has been shown that, under identical conditions of cell isolation, more complete digestion of heart muscle was observed in

  7. More Refined Experiments with Hemoglobin.

    ERIC Educational Resources Information Center

    Morin, Phillippe

    1985-01-01

    Discusses materials needed, procedures used, and typical results obtained for experiments designed to make a numerical stepwise study of the oxygenation of hemoglobin, myoglobin, and other oxygen carriers. (JN)

  8. Effects of Intermediates between Vitamins K2 and K3 on Mammalian DNA Polymerase Inhibition and Anti-Inflammatory Activity

    PubMed Central

    Mizushina, Yoshiyuki; Maeda, Jun; Irino, Yasuhiro; Nishida, Masayuki; Nishiumi, Shin; Kondo, Yasuyuki; Nishio, Kazuyuki; Kuramochi, Kouji; Tsubaki, Kazunori; Kuriyama, Isoko; Azuma, Takeshi; Yoshida, Hiromi; Yoshida, Masaru

    2011-01-01

    Previously, we reported that vitamin K3 (VK3), but not VK1 or VK2 (=MK-4), inhibits the activity of human DNA polymerase γ (pol γ). In this study, we chemically synthesized three intermediate compounds between VK2 and VK3, namely MK-3, MK-2 and MK-1, and investigated the inhibitory effects of all five compounds on the activity of mammalian pols. Among these compounds, MK-2 was the strongest inhibitor of mammalian pols α, κ and λ, which belong to the B, Y and X families of pols, respectively; whereas VK3 was the strongest inhibitor of human pol γ, an A-family pol. MK-2 potently inhibited the activity of all animal species of pol tested, and its inhibitory effect on pol λ activity was the strongest with an IC50 value of 24.6 μM. However, MK-2 did not affect the activity of plant or prokaryotic pols, or that of other DNA metabolic enzymes such as primase of pol α, RNA polymerase, polynucleotide kinase or deoxyribonuclease I. Because we previously found a positive relationship between pol λ inhibition and anti-inflammatory action, we examined whether these compounds could inhibit inflammatory responses. Among the five compounds tested, MK-2 caused the greatest reduction in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced acute inflammation in mouse ear. In addition, in a cell culture system using mouse macrophages, MK-2 displayed the strongest suppression of the production of tumor necrosis factor (TNF)-α induced by lipopolysaccharide (LPS). Moreover, MK-2 was found to inhibit the action of nuclear factor (NF)-κB. In an in vivo mouse model of LPS-evoked acute inflammation, intraperitoneal injection of MK-2 in mice led to suppression of TNF-α production in serum. In conclusion, this study has identified VK2 and VK3 intermediates, such as MK-2, that are promising anti-inflammatory candidates. PMID:21541047

  9. Human Hp1-1 and Hp2-2 Phenotype-Specific Haptoglobin Therapeutics Are Both Effective In Vitro and in Guinea Pigs to Attenuate Hemoglobin Toxicity

    PubMed Central

    Lipiski, Miriam; Deuel, Jeremy W.; Baek, Jin Hyen; Engelsberger, Wolfgang R.

    2013-01-01

    Abstract Aims: Infusion of purified haptoglobin (Hp) functions as an effective hemoglobin (Hb) scavenging therapeutic in animal models of hemolysis to prevent cardiovascular and renal injury. Epidemiologic studies demonstrate the phenotype heterogeneity of human Hp proteins and suggest differing vascular protective potential imparted by the dimeric Hp1-1 and the polymeric Hp2-2. Results: In vitro experiments and in vivo studies in guinea pigs were performed to evaluate phenotype-specific differences in Hp therapeutics. We found no differences between the two phenotypes in Hb binding and intravascular compartmentalization of Hb in vivo. Both Hp1-1 and Hp2-2 attenuate Hb-induced blood pressure response and renal iron deposition. These findings were consistent with equal prevention of Hb endothelial translocation. The modulation of oxidative Hb reactions by the two Hp phenotypes was not found to be different. Both phenotypes stabilize the ferryl (Fe4+) Hb transition state, provide heme retention within the complex, and prevent Hb-driven low-density lipoprotein (LDL) peroxidation. Hb-mediated peroxidation of LDL resulted in endothelial toxicity, which was equally blocked by the addition of Hp1-1 and Hp2-2. Innovation and Conclusion: The present data do not provide support for the concept that phenotype-specific Hp therapeutics offer differential efficacy in mitigating acute Hb toxicity. Antioxid. Redox Signal. 19, 1619–1633. PMID:23418677

  10. Metabonomic Analysis Reveals Efficient Ameliorating Effects of Acupoint Stimulations on the Menopause-caused Alterations in Mammalian Metabolism

    NASA Astrophysics Data System (ADS)

    Zhang, Limin; Wang, Yulan; Xu, Yunxiang; Lei, Hehua; Zhao, Ying; Li, Huihui; Lin, Xiaosheng; Chen, Guizhen; Tang, Huiru

    2014-01-01

    Acupoint stimulations are effective in ameliorating symptoms of menopause which is an unavoidable ageing consequence for women. To understand the mechanistic aspects of such treatments, we systematically analyzed the effects of acupoint laser-irradiation and catgut-embedding on the ovariectomy-induced rat metabolic changes using NMR and GC-FID/MS methods. Results showed that ovariectomization (OVX) caused comprehensive metabolic changes in lipid peroxidation, glycolysis, TCA cycle, choline and amino acid metabolisms. Both acupoint laser-irradiation and catgut-embedding ameliorated the OVX-caused metabonomic changes more effectively than hormone replacement therapy (HRT) with nilestriol. Such effects of acupoint stimulations were highlighted in alleviating lipid peroxidation, restoring glucose homeostasis and partial reversion of the OVX-altered amino acid metabolism. These findings provided new insights into the menopause effects on mammalian biochemistry and beneficial effects of acupoint stimulations in comparison with HRT, demonstrating metabonomics as a powerful approach for potential applications in disease prognosis and developments of effective therapies.

  11. Metabonomic Analysis Reveals Efficient Ameliorating Effects of Acupoint Stimulations on the Menopause-caused Alterations in Mammalian Metabolism

    PubMed Central

    Zhang, Limin; Wang, Yulan; Xu, Yunxiang; Lei, Hehua; Zhao, Ying; Li, Huihui; Lin, Xiaosheng; Chen, Guizhen; Tang, Huiru

    2014-01-01

    Acupoint stimulations are effective in ameliorating symptoms of menopause which is an unavoidable ageing consequence for women. To understand the mechanistic aspects of such treatments, we systematically analyzed the effects of acupoint laser-irradiation and catgut-embedding on the ovariectomy-induced rat metabolic changes using NMR and GC-FID/MS methods. Results showed that ovariectomization (OVX) caused comprehensive metabolic changes in lipid peroxidation, glycolysis, TCA cycle, choline and amino acid metabolisms. Both acupoint laser-irradiation and catgut-embedding ameliorated the OVX-caused metabonomic changes more effectively than hormone replacement therapy (HRT) with nilestriol. Such effects of acupoint stimulations were highlighted in alleviating lipid peroxidation, restoring glucose homeostasis and partial reversion of the OVX-altered amino acid metabolism. These findings provided new insights into the menopause effects on mammalian biochemistry and beneficial effects of acupoint stimulations in comparison with HRT, demonstrating metabonomics as a powerful approach for potential applications in disease prognosis and developments of effective therapies. PMID:24407431

  12. Two-photon excited fluorescence emission from hemoglobin

    NASA Astrophysics Data System (ADS)

    Sun, Qiqi; Zeng, Yan; Zhang, Wei; Zheng, Wei; Luo, Yi; Qu, Jianan Y.

    2015-03-01

    Hemoglobin, one of the most important proteins in blood, is responsible for oxygen transportation in almost all vertebrates. Recently, we discovered two-photon excited hemoglobin fluorescence and achieved label-free microvascular imaging based on the hemoglobin fluorescence. However, the mechanism of its fluorescence emission still remains unknown. In this work, we studied the two-photon excited fluorescence properties of the hemoglobin subunits, heme/hemin (iron (II)/(III) protoporphyrin IX) and globin. We first studied the properties of heme and the similar spectral and temporal characteristics of heme and hemoglobin fluorescence provide strong evidence that heme is the fluorophore in hemoglobin. Then we studied the fluorescence properties of hemin, globin and methemoglobin, and found that the hemin may have the main effect on the methemoglobin fluorescence and that globin has tryptophan fluorescence like other proteins. Finally, since heme is a centrosymmetric molecule, that the Soret band fluorescence of heme and hemoglobin was not observed in the single photon process in the previous study may be due to the parity selection rule. The discovery of heme two-photon excited fluorescence may open a new window for heme biology research, since heme as a cofactor of hemoprotein has many functions, including chemical catalysis, electron transfer and diatomic gases transportation.

  13. Diverse Non-genetic, Allele-Specific Expression Effects Shape Genetic Architecture at the Cellular Level in the Mammalian Brain.

    PubMed

    Huang, Wei-Chao; Ferris, Elliott; Cheng, Tong; Hörndli, Cornelia Stacher; Gleason, Kelly; Tamminga, Carol; Wagner, Janice D; Boucher, Kenneth M; Christian, Jan L; Gregg, Christopher

    2017-03-08

    Interactions between genetic and epigenetic effects shape brain function, behavior, and the risk for mental illness. Random X inactivation and genomic imprinting are epigenetic allelic effects that are well known to influence genetic architecture and disease risk. Less is known about the nature, prevalence, and conservation of other potential epigenetic allelic effects in vivo in the mouse and primate brain. Here we devise genomics, in situ hybridization, and mouse genetics strategies to uncover diverse allelic effects in the brain that are not caused by imprinting or genetic variation. We found allelic effects that are developmental stage and cell type specific, that are prevalent in the neonatal brain, and that cause mosaics of monoallelic brain cells that differentially express wild-type and mutant alleles for heterozygous mutations. Finally, we show that diverse non-genetic allelic effects that impact mental illness risk genes exist in the macaque and human brain. Our findings have potential implications for mammalian brain genetics. VIDEO ABSTRACT.

  14. Inhibitory effects of catechin derivatives on mammalian DNA polymerase and topoisomerase activities and mouse one-cell zygote development.

    PubMed

    Yoshida, Naoko; Kuriyama, Isoko; Yoshida, Hiromi; Mizushina, Yoshiyuki

    2013-03-01

    In this study, the inhibitory activities against DNA polymerases (pols) and DNA topoisomerases (topos) by eight major green tea catechin derivatives (flavan-3-ols) were investigated. Some catechins inhibited mammalian pols (α and β) and human topos (I and II), with (-)-epigallocatechin gallate (EGCg) the strongest inhibitor of both enzyme types, showing IC(50) values of 3.8-21.5 and 2.0-20.0 μM, respectively. EGCg did not affect the activities of plant (cauliflower) pol α or prokaryotic pols and showed no effect on the activities of other DNA metabolic enzymes tested. Next, a method was established for assay of mouse one-cell zygote development inhibition, the catechin derivatives screened for bioactivity, and the inhibition was assessed and their effects ranked as: EGCg > GCg > Cg > others. In the mouse one-cell zygote assay, EGCg at 50 μM increased abnormal cells and 75 μM of EGCg-induced apoptosis. The observed ranking of catechin derivative inhibition effects against mouse one-cell zygote development in vivo was similar to their ranking by topo inhibition in vitro rather than by pol inhibition; therefore, topo inhibition might have been effecting zygote development inhibition. These results suggested that catechin derivatives indeed reached the nuclear DNA where topo inhibition can occur, thus causing the observed cellular effects. From these findings, this zygote development inhibition assay will be useful as an anti-pregnant agent screening.

  15. Cellular bias on the microscale: probing the effects of digital microfluidic actuation on mammalian cell health, fitness and phenotype.

    PubMed

    Au, Sam H; Fobel, Ryan; Desai, Salil P; Voldman, Joel; Wheeler, Aaron R

    2013-08-01

    The potential benefits of using new technologies such as microfluidics for life science applications are exciting, but it is critical to understand and document potential biases imposed by these technologies on the observed results. Here, we report the first study of genome-level effects on cells manipulated by digital microfluidics. These effects were evaluated using a broad suite of tools: cell-based stress sensors for heat shock activation, single-cell COMET assays to probe changes in DNA integrity, and DNA microarrays and qPCR to evaluate changes in genetic expression. The results lead to two key observations. First, most DMF operating conditions tested, including those that are commonly used in the literature, result in negligible cell-stress or genome-level effects. Second, for DMF devices operated at high driving frequency (18 kHz) and with large driving electrodes (10 mm × 10 mm), there are significant damage to DNA integrity and differential genomic regulation. We hypothesize that these effects are caused by droplet heating. We recommend that for DMF applications involving mammalian cells that driving frequencies be kept low (≤ 10 kHz) and electrode sizes be kept small (≤ 5 mm) to avoid detrimental effects.

  16. The evolution of Root effect hemoglobins in the absence of intracellular pH protection of the red blood cell: insights from primitive fishes.

    PubMed

    Regan, Matthew D; Brauner, Colin J

    2010-06-01

    The Root effect, a reduction in blood oxygen (O(2)) carrying capacity at low pH, is used by many fish species to maximize O(2) delivery to the eye and swimbladder. It is believed to have evolved in the basal actinopterygian lineage of fishes, species that lack the intracellular pH (pH(i)) protection mechanism of more derived species' red blood cells (i.e., adrenergically activated Na(+)/H(+) exchangers; betaNHE). These basal actinopterygians may consequently experience a reduction in blood O(2) carrying capacity, and thus O(2) uptake at the gills, during hypoxia- and exercise-induced generalized blood acidoses. We analyzed the hemoglobins (Hbs) of seven species within this group [American paddlefish (Polyodon spathula), white sturgeon (Acipenser transmontanus), spotted gar (Lepisosteus oculatus), alligator gar (Atractosteus spatula), bowfin (Amia calva), mooneye (Hiodon tergisus), and pirarucu (Arapaima gigas)] for their Root effect characteristics so as to test the hypothesis of the Root effect onset pH value being lower than those pH values expected during a generalized acidosis in vivo. Analysis of the haemolysates revealed that, although each of the seven species displayed Root effects (ranging from 7.3 to 40.5% desaturation of Hb with O(2), i.e., Hb O(2) desaturation), the Root effect onset pH values of all species are considerably lower (ranging from pH 5.94 to 7.04) than the maximum blood acidoses that would be expected following hypoxia or exercise (pH(i) 7.15-7.3). Thus, although these primitive fishes possess Hbs with large Root effects and lack any significant red blood cell betaNHE activity, it is unlikely that the possession of a Root effect would impair O(2) uptake at the gills following a generalized acidosis of the blood. As well, it was shown that both maximal Root effect and Root effect onset pH values increased significantly in bowfin over those of the more basal species, toward values of similar magnitude to those of most of the more derived

  17. Development of an immunoassay to detect benzene adducts in hemoglobin

    SciTech Connect

    Grassman, J.A.

    1993-01-01

    The purpose of this project was to develop an immunoassay to detect the adducts formed in hemoglobin after exposure to benzene, which is known to cause bone marrow degeneration and acute myelogenous leukemia. The use of benzene-adduct detection as a biological monitoring method would permit measurement of low exposures and exposures sustained weeks earlier. The reactivity of hydroquinone, an important benzene metabolite, with blood proteins and amino acids was investigated in order to decide which antigens and analytes were likely to be suitable for immunoassay development. The second section determined the combination of benzene-metabolite and antigen need to produce an immunoassay with the requisite low detection limit and specificity. The immunoassays with the best performance were tested on hemoglobin from benzene-exposed mice. In vitro studies showed that hydroquinone efficiently formed adducts with erythrocyte membranes and hemoglobin but not with albumin. Adduction efficiency was greater in incubations using purified hemoglobin than whole blood. Cysteine accounted for 15 to 27% of the adducts formed by hydroquinone. The site of the other adducts were not identified although there was evidence that the hemoglobin heme was adducted. Adducts were found on only 1 of the 2 globin chains. Tryptic digestion of the globin failed to associate the adducts with a specific peptide. Antigens made from hydroquinone-adducted hemoglobin but not hydroquinone-adducted cysteines coupled to carrier proteins effectively elicited adduct-specific antibodies. Interference due to reactivity to hemoglobin was controlled by using uniform quantities of hemoglobin in all wells. The mid-range of the best assays were approximately 12 pmoles HQ per well. Antibodies directed toward hemoglobin adducted with the benzene metabolites phenol, catechol and 1,2,4-trihydroxybenzene were also made. The performance of the anti-1,2,4-trihydroxybenzene were suitable for quantitative immunoassays.

  18. Role of uteroferrin in placental iron transport: effect of maternal iron treatment on fetal iron and uteroferrin content and neonatal hemoglobin.

    PubMed

    Ducsay, C A; Buhi, W C; Bazer, F W; Roberts, R M; Combs, G E

    1984-11-01

    Uteroferrin, an Fe-containing, progesterone-induced glycoprotein is involved in maternal to fetal Fe transport in swine. These studies examined the effect of im Fe injection of dam on conceptus and piglet Fe stores. In Exp. I, eight gilts were bred and assigned to either treatment I (no Fe injections) or treatment II (total of 22 mg iron-dextran/kg body weight on d 40, 45, 50, 55 and 60 of gestation) and hysterectomized on d 90 to determine whether Fe injections increased Fe stores in the conceptus. Total Fe in allantoic fluid (P less than .10) as well as uteroferrin concentration (P less than .05) and total uteroferrin (P less than .05) in placentae were greater for gilts in treatment II. In Exp. II, 19 cross-bred sows were bred and assigned to treatments I and II (d 40, 50 and 60 of gestation), as in Exp. I, and treatment III (total of 22 mg iron-dextran/kg body weight on d 90, 100 and 110 of gestation) to determine effects of treatment on hemoglobin (Hb) values of the piglets at 8 +/- 1 h and d 4 postpartum. Piglets from treatment II had higher (P less than .01) Hb at 8 +/- 1 h, but not on d 4 postpartum. Experiment III was a replication of Exp. II except that Hb values were determined at 8 +/- 1 h, d 4 and d 7 postpartum. On d 7, piglets from treatment II had higher (P less than .05) Hb, but differences at 8 +/- 1 h and d 4 were not significant (P greater than .10).(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Grape polyphenols inhibit Akt/mammalian target of rapamycin signaling and potentiate the effects of gefitinib in breast cancer.

    PubMed

    Castillo-Pichardo, Linette; Dharmawardhane, Suranganie F

    2012-01-01

    We recently reported that a combination of dietary grape polyphenols resveratrol, quercetin, and catechin (RQC), at low concentrations, was effective at inhibiting metastatic cancer progression. Herein, we investigate the molecular mechanisms of RQC in breast cancer and explore the potential of RQC as a potentiation agent for the epidermal growth factor receptor (EGFR) therapeutic gefitinib. Our in vitro experiments showed RQC induced apoptosis in gefitinib-resistant breast cancer cells via regulation of a myriad of proapoptotic proteins. Because the Akt/mammalian target of rapamycin (mTOR) signaling pathway is often elevated during development of anti-EGFR therapy resistance, the effect of RQC on the mTOR upstream effector Akt and the negative regulator AMP kinase (AMPK) was investigated. RQC was found to reduce Akt activity, induce the activation of AMPK, and inhibit mTOR signaling in breast cancer cells. Combined RQC and gefitinib decreased gefitinib resistant breast cancer cell viability to a greater extent than RQC or gefitinib alone. Moreover, RQC inhibited Akt and mTOR and activated AMPK even in the presence of gefitinib. Our in vivo experiments showed combined RQC and gefitinib was more effective than the individual treatments at inhibiting mammary tumor growth and metastasis in nude mice. Therefore, RQC treatment inhibits breast cancer progression and may potentiate anti-EGFR therapy by inhibition of Akt/mTOR signaling.

  20. Vitreoscilla hemoglobin renders Enterobacter aerogenes highly susceptible to heavy metals.

    PubMed

    Geckil, Hikmet; Arman, Ahmet; Gencer, Salih; Ates, Burhan; Yilmaz, H Ramazan

    2004-12-01

    When expressed in heterologous microorganisms Vitreoscilla hemoglobin (VHb) acts as oxygen storage and causes a higher oxygen uptake. In this study, the effect of this protein on growth, sensitivity and antioxidant properties of Enterobacter aerogenes exposed to metal stress was investigated. The strain expressing VHb was more sensitive to mercury and cadmium as the minimal inhibitory concentration (MIC) for these metals was up to 2-fold lower in this strain than the host and the recombinant strain carrying a comparable plasmid. At lower concentrations than MIC, the metals partially limited growth and caused an inhibition proportional to metal concentration applied. The growth pattern of VHb expressing strain was also distinctly different from other two non-hemoglobin strains. The hemoglobin containing strain showed substantially higher superoxide dismuates (SOD) activity than the non-hemoglobin strains, while catalase levels were similar in all strains. All strains exposed to copper, however, showed similar MIC values, growth patterns, and SOD and catalase levels.

  1. Hemoglobin Wayne Trait with Incidental Polycythemia.

    PubMed

    Ambelil, Manju; Nguyen, Nghia; Dasgupta, Amitava; Risin, Semyon; Wahed, Amer

    2017-01-01

    Hemoglobinopathies, caused by mutations in the globin genes, are one of the most common inherited disorders. Many of the hemoglobin variants can be identified by hemoglobin analysis using conventional electrophoresis and high performance liquid chromatography; however hemoglobin DNA analysis may be necessary in other cases for confirmation. Here, we report a case of a rare alpha chain hemoglobin variant, hemoglobin Wayne, in a 47-year-old man who presented with secondary polycythemia. Capillary zone electrophoresis and high performance liquid chromatography revealed a significant amount of a hemoglobin variant, which was further confirmed by hemoglobin DNA sequencing as hemoglobin Wayne. Since the patient was not homozygous for hemoglobin Wayne, which is associated with secondary polycythemia, the laboratory diagnosis in this case was critical in ruling out hemoglobinopathy as the etiology of his polycythemia.

  2. Effects of enhanced UV-B radiation on secondary metabolites in forage plants and potential consequences for multiple trophic responses involving mammalian herbivores

    NASA Astrophysics Data System (ADS)

    Thines, Nicole J.; Bassman, John H.; Shipley, Lisa A.; Slusser, James R.

    2004-10-01

    Herbivores represent the interface between primary production and higher trophic levels. The effects of enhanced UV-B radiation on microbes, invertebrate herbivores, and detritivores has received limited study in both terrestrial and aquatic ecosystems. However, although direct effects (e.g. melanoma, cataracts) on mammals have been documented, indirect effects (e.g., resulting from changes in plant chemistry) of enhanced UV-B on mammalian herbivores have not been evaluated. Although the diet of mammalian herbivores has little effect on nutritional quality for their associated predators, to the extent changes in plant chemistry affect aspects of population dynamics (e.g., growth, fecundity, densities), higher trophic levels can be affected. In this study, different forage species of varying inherent levels of key secondary metabolites are being grown in the field under either ambient or ambient plus supplemental UV-B radiation simulating a 15% stratospheric ozone depletion for Pullman, Washington. At various time intervals, foliage is being sampled and analyzed for changes in secondary metabolites and other attributes. Using controlled feeding trials, changes in plant secondary metabolites are being related to preference and digestibility in specialist and generalist mammalian hindgut herbivores, digestion in ruminants and non-ruminants, and to selected aspects of population dynamics in mammalian herbivores. Results suggest how UV-B-induced changes in plant secondary chemistry affect animal nutrition, and thus animal productivity in a range of mammalian herbivores. Reductions in palatability and digestibility of plant material along with reductions in fecundity and other aspects of population dynamics could have significant economic ramifications for farmers, ranchers and wildlife biologists.

  3. Free heme and sickle hemoglobin polymerization

    NASA Astrophysics Data System (ADS)

    Uzunova, Veselina V.

    This work investigates further the mechanism of one of the most interesting of the protein self-assembly systems---the polymerization of sickle hemoglobin and the role of free heme in it. Polymerization of sickle hemoglobin is the primary event in the pathology of a chronic hemolytic condition called sickle cell anemia with complex pathogenesis, unexplained variability and symptomatic treatment. Auto-oxidation develops in hemoglobin solutions exposed to room temperature and causes release of ferriheme. The composition of such solutions is investigated by mass spectrometry. Heme dimers whose amount corresponds to the initial amounts of heme released from the protein are followed. Differences in the dimer peak height are established for hemoglobin variants A, S and C and depending on the exposure duration. The effects of free heme on polymerization kinetics are studied. Growth rates and two characteristic parameters of nucleation are measured for stored Hb S. After dialysis of polymerizing solutions, no spherulites are detected at moderately high supersaturation and prolonged exposure times. The addition of 0.16-0.26 mM amounts of heme to dialyzed solutions leads to restoration of polymerization. The measured kinetic parameters have higher values compared to the ones before dialysis. The amount of heme in non-dialyzed aged solution is characterized using spectrophotometry. Three methods are used: difference in absorbance of dialyzed and non-dialyzed solutions, characteristic absorbance of heme-albumin complex and absorbance of non-dialyzed solutions with added potassium cyanide. The various approaches suggest the presence of 0.12 to 0.18 mM of free ferriheme in such solutions. Open questions are whether the same amounts of free heme are present in vivo and whether the same mechanism operates intracellulary. If the answer to those questions is positive, then removal of free heme from erythrocytes can influence their readiness to sickle.

  4. Fetal hemoglobin in sickle cell anemia.

    PubMed

    Akinsheye, Idowu; Alsultan, Abdulrahman; Solovieff, Nadia; Ngo, Duyen; Baldwin, Clinton T; Sebastiani, Paola; Chui, David H K; Steinberg, Martin H

    2011-07-07

    Fetal hemoglobin (HbF) is the major genetic modulator of the hematologic and clinical features of sickle cell disease, an effect mediated by its exclusion from the sickle hemoglobin polymer. Fetal hemoglobin genes are genetically regulated, and the level of HbF and its distribution among sickle erythrocytes is highly variable. Some patients with sickle cell disease have exceptionally high levels of HbF that are associated with the Senegal and Saudi-Indian haplotype of the HBB-like gene cluster; some patients with different haplotypes can have similarly high HbF. In these patients, high HbF is associated with generally milder but not asymptomatic disease. Studying these persons might provide additional insights into HbF gene regulation. HbF appears to benefit some complications of disease more than others. This might be related to the premature destruction of erythrocytes that do not contain HbF, even though the total HbF concentration is high. Recent insights into HbF regulation have spurred new efforts to induce high HbF levels in sickle cell disease beyond those achievable with the current limited repertory of HbF inducers.

  5. The Effects of Allicin, a Reactive Sulfur Species from Garlic, on a Selection of Mammalian Cell Lines

    PubMed Central

    Gruhlke, Martin C. H.; Nicco, Carole; Batteux, Frederic; Slusarenko, Alan J.

    2016-01-01

    Garlic (Allium sativum L.) has been used as a spice and medicinal plant since ancient times. Garlic produces the thiol-reactive defence substance, allicin, upon wounding. The effects of allicin on human lung epithelium carcinoma (A549), mouse fibroblast (3T3), human umbilical vein endothelial cell (HUVEC), human colon carcinoma (HT29) and human breast cancer (MCF7) cell lines were tested. To estimate toxic effects of allicin, we used a standard MTT-test (methylthiazoltetrazolium) for cell viability and 3H-thymidine incorporation for cell proliferation. The glutathione pool was measured using monobromobimane and the formation of reactive species was identified using 2′,7′-dichlorofluoresceine-diacetate. The YO-PRO-1 iodide staining procedure was used to estimate apoptosis. Allicin reduced cell viability and cell proliferation in a concentration dependent manner. In the bimane test, it was observed that cells treated with allicin showed reduced fluorescence, suggesting glutathione oxidation. The cell lines tested differed in sensitivity to allicin in regard to viability, cell proliferation and glutathione oxidation. The 3T3 and MCF-7 cells showed a higher proportion of apoptosis compared to the other cell types. These data show that mammalian cell lines differ in their sensitivity and responses to allicin. PMID:28035949

  6. Reactions of arsine with hemoglobin

    SciTech Connect

    Hatlelid, K.M.; Brailsford, C.; Carter, D.E.

    1996-02-09

    The mechanism of arsine (AsH{sub 3}) induced hemolysis was studied in vitro using isolated red blood cells (RBCs) from the rat or dog. AsH{sub 3}-induced hemolysis of dog red blood cells was completely blocked by carbon monoxide (CO) preincubation and was reduced by pure oxygen (O{sub 2}) compared to incubations in air. Since CO and O{sub 2} bind to heme and also reduced hemolysis, these results suggested a reaction between AsH{sub 3} and hemoglobin in the hemeligand binding pocket or with the heme iron. Further, sodium nitrite induction of methemoglobin (metHb) to 85% and 34% of total Hb in otherwise intact RBCs resulted in 56% and 16% decreases in hemolysis, respectively, after incubation for 4 h. This provided additional evidence for the involvement of hemoglobin in the AsH{sub 3}-induced hemolysis mechanism. Reactions between AsH{sub 3} and hemoglobin were studied in solutions of purified dog hemoglobin. Spectrophotometric studies of the reaction of AsH{sub 3} with various purified hemoglobin species revealed that AsH{sub 3} reacted with HbO{sub 2} to produce metHb and, eventually, degraded Hb characterized by gross precipitation of the protein. AsH{sub 3} did not alter the spectrum of deoxyHb and did not cause degradation of metHb in oxygen, but bound to and reduced metHb in the absence of oxygen. These data indicate that a reaction of AsH{sub 3} with oxygenated hemoglobin, HbO{sub 2}, may lead to hemolysis, but there are reactions between AsH{sub 3} and metHb that may not be directly involved in the hemolytic process. 17 refs., 6 figs.

  7. A review of variant hemoglobins interfering with hemoglobin A1c measurement.

    PubMed

    Little, Randie R; Roberts, William L

    2009-05-01

    Hemoglobin A1c (HbA1c) is used routinely to monitor long-term glycemic control in people with diabetes mellitus, as HbA1c is related directly to risks for diabetic complications. The accuracy of HbA1c methods can be affected adversely by the presence of hemoglobin (Hb) variants or elevated levels of fetal hemoglobin (HbF). The effect of each variant or elevated HbF must be examined with each specific method. The most common Hb variants worldwide are HbS, HbE, HbC, and HbD. All of these Hb variants have single amino acid substitutions in the Hb beta chain. HbF is the major hemoglobin during intrauterine life; by the end of the first year, HbF falls to values close to adult levels of approximately 1%. However, elevated HbF levels can occur in certain pathologic conditions or with hereditary persistence of fetal hemoglobin. In a series of publications over the past several years, the effects of these four most common Hb variants and elevated HbF have been described. There are clinically significant interferences with some methods for each of these variants. A summary is given showing which methods are affected by the presence of the heterozygous variants S, E, C, and D and elevated HbF. Methods are divided by type (immunoassay, ion-exchange high-performance liquid chromatography, boronate affinity, other) with an indication of whether the result is artificially increased or decreased by the presence of a Hb variant. Laboratorians should be aware of the limitations of their method with respect to these interferences.

  8. Effect of Emetine on T-2 Toxin-Induced Inhibition of Protein Synthesis in Mammalian Cells

    DTIC Science & Technology

    1993-01-01

    dependent manner. The dose-response curves for these potent trichothecenes, deoxynivalenol , T-2 tetraol and verru- two effects were nearly identical...response of cells to T-2 To RecoPa y Tru tetraol, deoxynivalenol and verrucarol (fig. 5, D-F). Covetldw 0 1 4 8 As noted earlier, the data in figures 4 and... deoxynivalenol or T-2 tetraol. toxin-cell association was not a generalized nonspecific effect associated with any inhibitor of protein synthesis. Discussion

  9. Pancreatic ascites hemoglobin contributes to the systemic response in acute pancreatitis.

    PubMed

    Pérez, Salvador; Pereda, Javier; Sabater, Luis; Sastre, Juan

    2015-04-01

    Upon hemolysis extracellular hemoglobin causes oxidative stress and cytotoxicity due to its peroxidase activity. Extracellular hemoglobin may release free hemin, which increases vascular permeability, leukocyte recruitment, and adhesion molecule expression. Pancreatitis-associated ascitic fluid is reddish and may contain extracellular hemoglobin. Our aim has been to determine the role of extracellular hemoglobin in the local and systemic inflammatory response during severe acute pancreatitis in rats. To this end we studied taurocholate-induced necrotizing pancreatitis in rats. First, extracellular hemoglobin in ascites and plasma was quantified and the hemolytic action of ascitic fluid was tested. Second, we assessed whether peritoneal lavage prevented the increase in extracellular hemoglobin in plasma during pancreatitis. Third, hemoglobin was purified from rat erythrocytes and administered intraperitoneally to assess the local and systemic effects of ascitic-associated extracellular hemoglobin during acute pancreatitis. Extracellular hemoglobin and hemin levels markedly increased in ascitic fluid and plasma during necrotizing pancreatitis. Peroxidase activity was very high in ascites. The peritoneal lavage abrogated the increase in extracellular hemoglobin in plasma. The administration of extracellular hemoglobin enhanced ascites; dramatically increased abdominal fat necrosis; upregulated tumor necrosis factor-α, interleukin-1β, and interleukin-6 gene expression; and decreased expression of interleukin-10 in abdominal adipose tissue during pancreatitis. Extracellular hemoglobin enhanced the gene expression and protein levels of vascular endothelial growth factor (VEGF) and other hypoxia-inducible factor-related genes in the lung. Extracellular hemoglobin also increased myeloperoxidase activity in the lung. In conclusion, extracellular hemoglobin contributes to the inflammatory response in severe acute pancreatitis through abdominal fat necrosis and inflammation

  10. Differential effects of fluoxetine enantiomers in mammalian neural and cardiac tissues.

    PubMed

    Magyar, János; Rusznák, Zoltán; Harasztosi, Csaba; Körtvély, Agnes; Pacher, Pál; Bányász, Tamás; Pankucsi, Csaba; Kovács, László; Szûcs, Géza; Nánási, Péter P; Kecskeméti, Valéria

    2003-04-01

    Racemic fluoxetine is a widely used SSRI antidepressant compound having also anticonvulsant effect. In addition, it was shown that it blocked several types of voltage gated ion channels including neural and cardiac calcium channels. In the present study the effects of enantiomers of fluoxetine (R(-)-fluoxetine and S(+)-fluoxetine) were compared on neuronal and cardiac voltage-gated Ca2+ channels using the whole cell configuration of patch clamp techniques, and the anticonvulsant action of these enantiomers was also evaluated in a mouse epilepsy model. In isolated pyramidal neurons of the dorsal cochlear nucleus of the rat the effect of fluoxetine (S(+), R(-) and racemic) was studied on the Ca2+ channels by measuring peak Ba2+ current during ramp depolarizations. All forms of fluoxetine reduced the Ba2+ current of the pyramidal cells in a concentration-dependent manner, with a Kd value of 22.3+/-3.6 microM for racemic fluoxetine. This value of Kd was higher by one order of magnitude than found in cardiac myocytes with fluoxetine enantiomers (2.4+/-0.1 and 2.8+/-0.2 microM). Difference between the effects of the two enantiomers on neuronal Ba2+ current was observed only at 5 microM concentration: R(-)-fluoxetine inhibited 28+/-3% of the peak current, while S(+)-fluoxetine reduced the current by 18+/-2% (n=13, P<0.05). In voltage clamped canine ventricular cardiomyocytes both enantiomers of fluoxetine caused a reversible concentration-dependent block of the peak Ca2+ current measured at 0 mV. Significant differences between the two enantiomers in this blocking effect was observed at low concentrations only: S(+)-fluoxetine caused a higher degree of block than R(-)-fluoxetine (56.3+/-2.2% versus 49.1+/-2.2% and 95.5+/-0.9% versus 84.5+/-3.1% block with 3 and 10 microM S(+) and R(-)-fluoxetine, respectively, P<0.05, n=5). Studied in current clamp mode, micromolar concentrations of fluoxetine shortened action potential duration of isolated ventricular cells, while higher

  11. Induction of a bystander mutagenic effect of alpha particles in mammalian cells

    NASA Technical Reports Server (NTRS)

    Zhou, H.; Randers-Pehrson, G.; Waldren, C. A.; Vannais, D.; Hall, E. J.; Hei, T. K.; Chatterjee, A. (Principal Investigator)

    2000-01-01

    Ever since the discovery of X-rays was made by Rontgen more than a hundred years ago, it has always been accepted that the deleterious effects of ionizing radiation such as mutation and carcinogenesis are attributable mainly to direct damage to DNA. Although evidence based on microdosimetric estimation in support of a bystander effect appears to be consistent, direct proof of such extranuclear/extracellular effects are limited. Using a precision charged particle microbeam, we show here that irradiation of 20% of randomly selected A(L) cells with 20 alpha particles each results in a mutant fraction that is 3-fold higher than expected, assuming no bystander modulation effect. Furthermore, analysis by multiplex PCR shows that the types of mutants induced are significantly different from those of spontaneous origin. Pretreatment of cells with the radical scavenger DMSO had no effect on the mutagenic incidence. In contrast, cells pretreated with a 40 microM dose of lindane, which inhibits cell-cell communication, significantly decreased the mutant yield. The doses of DMSO and lindane used in these experiments are nontoxic and nonmutagenic. We further examined the mutagenic yield when 5-10% of randomly selected cells were irradiated with 20 alpha particles each. Results showed, likewise, a higher mutant yield than expected assuming no bystander effects. Our studies provide clear evidence that irradiated cells can induce a bystander mutagenic response in neighboring cells not directly traversed by alpha particles and that cell-cell communication process play a critical role in mediating the bystander phenomenon.

  12. Switching Patients with Non-Dialysis Chronic Kidney Disease from Oral Iron to Intravenous Ferric Carboxymaltose: Effects on Erythropoiesis-Stimulating Agent Requirements, Costs, Hemoglobin and Iron Status

    PubMed Central

    Toblli, Jorge Eduardo; Di Gennaro, Federico

    2015-01-01

    Background Patients with non-dialysis-dependent chronic kidney disease (ND-CKD) often receive an erythropoiesis-stimulating agent (ESA) and oral iron treatment. This study evaluated whether a switch from oral iron to intravenous ferric carboxymaltose can reduce ESA requirements and improve iron status and hemoglobin in patients with ND-CKD. Methods This prospective, single arm and single-center study included adult patients with ND-CKD (creatinine clearance ≤40 mL/min), hemoglobin 11–12 g/dL and iron deficiency (ferritin <100 μg/L or transferrin saturation <20%), who were regularly treated with oral iron and ESA during 6 months prior to inclusion. Study patients received an intravenous ferric carboxymaltose dose of 1,000 mg iron, followed by a 6-months ESA/ ferric carboxymaltose maintenance regimen (target: hemoglobin 12 g/dL, transferrin saturation >20%). Outcome measures were ESA dose requirements during the observation period after initial ferric carboxymaltose treatment (primary endpoint); number of hospitalizations and transfusions, renal function before and after ferric carboxymaltose administration, number of adverse reactions (secondary endpoints). Hemoglobin, mean corpuscular volume, ferritin and transferrin saturation were measured monthly from baseline until end of study. Creatinine clearance, proteinuria, C-reactive protein, aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase bimonthly from baseline until end of study. Results Thirty patients were enrolled (age 70.1±11.4 years; mean±SD). Mean ESA consumption was significantly reduced by 83.2±10.9% (from 41,839±3,668 IU/patient to 6,879±4,271 IU/patient; p<0.01). Hemoglobin increased by 0.7±0.3 g/dL, ferritin by 196.0±38.7 μg/L and transferrin saturation by 5.3±2.9% (month 6 vs. baseline; all p<0.01). No ferric carboxymaltose-related adverse events were reported and no patient withdrew or required transfusions during the study. Conclusion Among patients with ND

  13. Aerobic expression of Vitreoscilla hemoglobin improves the growth performance of CHO-K1 cells.

    PubMed

    Juárez, Mariana; González-De la Rosa, Claudia H; Memún, Elisa; Sigala, Juan-Carlos; Lara, Alvaro R

    2017-03-01

    Inefficient carbon metabolism is a relevant issue during the culture of mammalian cells for the production of biopharmaceuticals. Therefore, cell engineering strategies to improve the metabolic and growth performance of cell lines are needed. The expression of Vitreoscilla stercoraria hemoglobin (VHb) has been shown to significantly reduce overflow metabolism and improve the aerobic growth of bacteria. However, the effects of VHb on mammalian cells have been rarely studied. Here, the impact of VHb on growth and lactate accumulation during CHO-K1 cell culture was investigated. For this purpose, CHO-K1 cells were transfected with plasmids carrying the vgb or gfp gene to express VHb or green fluorescence protein (GFP), respectively. VHb expression increased the specific growth rate and biomass yields on glucose and glutamine by 60 %, and reduced the amount of lactate produced per cell by 40 %, compared to the GFP-expression controls. Immunofluorescence microscopy showed that VHb is distributed in the cytoplasm and organelles, which support the hypothesis that VHb could serve as an oxygen carrier, enhancing aerobic respiration. These results are useful for the development of better producing cell lines for industrial applications.

  14. Cytotoxic Effects of Hexavalent and Trivalent Chromium on Mammalian Cells In Vitro

    PubMed Central

    Levis, A. G.; Bianchi, V.; Tamino, G.; Pegoraro, B.

    1978-01-01

    The cytotoxic effects of hexavalent (k2Cr2O7) and trivalent (CrCl3) chromium compounds have been studied in cultured hamster fibroblasts (BHK line) and human epithelial-like cells (HEp line). K2Cr2O7 stimulates the uptake of labelled thymidine into the soluble intracellular pool (the stimulation of nucleoside uptake represents a specific effect of Cr6+) while Cr3+ always exerts an inhibitory action. DNA Synthesis is inhibited by treatment with both chromium compounds, but especially by K2Cr2O7. Moreover, the effective CrCl3 concentrations reduce the sensitivity of DNA and RNA to hydrolysis with perchloric acid. Treatments with k2Cr2O7 in balanced salt solution, where Cr6+ reduction is less marked, induce more pronounced cytotoxic effects than treatments in complete growth medium. HEp cells turned out to be more sensitive to K2Cr2O7 than BHK fibroblasts: in the former line TdR uptake is less stimulated, DNA synthesis and cell survival are more affected. Survival of BHK cells to K2Cr2O7 indicates a multi-hit mechanism of cell inactivation, the extrapolation number being about 10. On the basis of quantitative Cr determinations in the treatment solutions and in the treated cells, the cytotoxic effects of Cr are attributed to the action of Cr6+ at the plasma membrane level on the mechanisms involved in nucleoside uptake, and to the interaction of Cr3+ at the intracellular level with nucleophilic targets on the DNA molecule. PMID:205233

  15. Mutant quantity and quality in mammalian cells (AL) exposed to cesium-137 gamma radiation: effect of caffeine

    NASA Technical Reports Server (NTRS)

    McGuinness, S. M.; Shibuya, M. L.; Ueno, A. M.; Vannais, D. B.; Waldren, C. A.; Chatterjee, A. (Principal Investigator)

    1995-01-01

    We examined the effect of caffeine (1,3,7-trimethylxanthine) on the quantity and quality of mutations in cultured mammalian AL human-hamster hybrid cells exposed to 137Cs gamma radiation. At a dose (1.5 mg/ml for 16 h) that reduced the plating efficiency (PE) by 20%, caffeine was not itself a significant mutagen, but it increased by approximately twofold the slope of the dose-response curve for induction of S1- mutants by 137Cs gamma radiation. Molecular analysis of 235 S1- mutants using a series of DNA probes mapped to the human chromosome 11 in the AL hybrid cells revealed that 73 to 85% of the mutations in unexposed cells and in cells treated with caffeine alone, 137Cs gamma rays alone or 137Cs gamma rays plus caffeine were large deletions involving millions of base pairs of DNA. Most of these deletions were contiguous with the region of the MIC1 gene at 11p13 that encodes the S1 cell surface antigen. In other mutants that had suffered multiple marker loss, the deletions were intermittent along chromosome 11. These "complex" mutations were rare for 137Cs gamma irradiation (1/63 = 1.5%) but relatively prevalent (23-50%) for other exposure conditions. Thus caffeine appears to alter both the quantity and quality of mutations induced by 137Cs gamma irradiation.

  16. Radiation-induced bystander effect and adaptive response in mammalian cells

    NASA Technical Reports Server (NTRS)

    Zhou, H.; Randers-Pehrson, G.; Waldren, C. A.; Hei, T. K.

    2004-01-01

    Two conflicting phenomena, bystander effect and adaptive response, are important in determining the biological responses at low doses of radiation and have the potential to impact the shape of the dose-response relationship. Using the Columbia University charged-particle microbeam and the highly sensitive AL cell mutagenic assay, we show here that non-irradiated cells acquire mutagenesis through direct contact with cells whose nuclei have been traversed with a single alpha particle each. Pretreatment of cells with a low dose of X-rays four hours before alpha particle irradiation significantly decreased this bystander mutagenic response. Results from the present study address some of the fundamental issues regarding both the actual target and radiation dose effect and can contribute to our current understanding in radiation risk assessment. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  17. Effects of Acute Administration of Ketorolac on Mammalian Vestibular Sensory Evoked Potentials

    PubMed Central

    Gaines, G Christopher; Jones, Timothy A

    2013-01-01

    The nonsteroidal antiinflammatory drug (NSAID) ketorolac is a candidate for use as a supplemental analgesic during major surgery in anesthetized rodents. The use of ketorolac during surgery is believed to reduce the anesthetic dose required to achieve and maintain an adequate surgical plane, thus improving the physiologic condition and survival of animals during long experimental procedures. Ketorolac has reported side effects that include dizziness, ear pain, hearing loss, tinnitus, and vertigo in humans, but ketorolac has not been reported to affect the vestibular system in animals. To investigate this possibility, we evaluated the acute effects of ketorolac on vestibular compound action potentials in C57BL/6 mice. Linear vestibular sensory-evoked potentials (VsEP) were recorded during the administration of ketorolac at doses 3 to 14 times the effective analgesic dose. VsEP results for ketorolac were compared with those from a control group maintained under anesthesia for the same period. Ketorolac did not significantly affect the temporal profiles of response latencies and amplitudes or the rate of change in response measures over time between controls and ketorolac-treated mice. These findings demonstrate that ketorolac can be used as an analgesic to supplement anesthesia in mice without concerns of modifying the amplitudes and latencies of the linear VsEP. PMID:23562034

  18. Effects of acute administration of ketorolac on mammalian vestibular sensory evoked potentials.

    PubMed

    Gaines, G Christopher; Jones, Timothy A

    2013-01-01

    The nonsteroidal antiinflammatory drug (NSAID) ketorolac is a candidate for use as a supplemental analgesic during major surgery in anesthetized rodents. The use of ketorolac during surgery is believed to reduce the anesthetic dose required to achieve and maintain an adequate surgical plane, thus improving the physiologic condition and survival of animals during long experimental procedures. Ketorolac has reported side effects that include dizziness, ear pain, hearing loss, tinnitus, and vertigo in humans, but ketorolac has not been reported to affect the vestibular system in animals. To investigate this possibility, we evaluated the acute effects of ketorolac on vestibular compound action potentials in C57BL/6 mice. Linear vestibular sensory-evoked potentials (VsEP) were recorded during the administration of ketorolac at doses 3 to 14 times the effective analgesic dose. VsEP results for ketorolac were compared with those from a control group maintained under anesthesia for the same period. Ketorolac did not significantly affect the temporal profiles of response latencies and amplitudes or the rate of change in response measures over time between controls and ketorolac-treated mice. These findings demonstrate that ketorolac can be used as an analgesic to supplement anesthesia in mice without concerns of modifying the amplitudes and latencies of the linear VsEP.

  19. Hemoglobin in a coacervate system.

    PubMed

    Ecanow, J; Ecanow, D; Ecanow, B

    1990-01-01

    Hemoglobin dissolved in a coacervate system shows the properties of a resuscitation fluid. In the coacervate system used, the equilibrium phase was the colloid rich phase. We propose a new definition of the coacervate phase to be that phase in a coacervate system which is most dissimilar to water in its physical chemical properties.

  20. A Comparison of the Effects of Three GM Corn Varieties on Mammalian Health

    PubMed Central

    de Vendômois, Joël Spiroux; Roullier, François; Cellier, Dominique; Séralini, Gilles-Eric

    2009-01-01

    We present for the first time a comparative analysis of blood and organ system data from trials with rats fed three main commercialized genetically modified (GM) maize (NK 603, MON 810, MON 863), which are present in food and feed in the world. NK 603 has been modified to be tolerant to the broad spectrum herbicide Roundup and thus contains residues of this formulation. MON 810 and MON 863 are engineered to synthesize two different Bt toxins used as insecticides. Approximately 60 different biochemical parameters were classified per organ and measured in serum and urine after 5 and 14 weeks of feeding. GM maize-fed rats were compared first to their respective isogenic or parental non-GM equivalent control groups. This was followed by comparison to six reference groups, which had consumed various other non-GM maize varieties. We applied nonparametric methods, including multiple pairwise comparisons with a False Discovery Rate approach. Principal Component Analysis allowed the investigation of scattering of different factors (sex, weeks of feeding, diet, dose and group). Our analysis clearly reveals for the 3 GMOs new side effects linked with GM maize consumption, which were sex- and often dose-dependent. Effects were mostly associated with the kidney and liver, the dietary detoxifying organs, although different between the 3 GMOs. Other effects were also noticed in the heart, adrenal glands, spleen and haematopoietic system. We conclude that these data highlight signs of hepatorenal toxicity, possibly due to the new pesticides specific to each GM corn. In addition, unintended direct or indirect metabolic consequences of the genetic modification cannot be excluded. PMID:20011136

  1. A comparison of the effects of three GM corn varieties on mammalian health.

    PubMed

    de Vendômois, Joël Spiroux; Roullier, François; Cellier, Dominique; Séralini, Gilles-Eric

    2009-12-10

    We present for the first time a comparative analysis of blood and organ system data from trials with rats fed three main commercialized genetically modified (GM) maize (NK 603, MON 810, MON 863), which are present in food and feed in the world. NK 603 has been modified to be tolerant to the broad spectrum herbicide Roundup and thus contains residues of this formulation. MON 810 and MON 863 are engineered to synthesize two different Bt toxins used as insecticides. Approximately 60 different biochemical parameters were classified per organ and measured in serum and urine after 5 and 14 weeks of feeding. GM maize-fed rats were compared first to their respective isogenic or parental non-GM equivalent control groups. This was followed by comparison to six reference groups, which had consumed various other non-GM maize varieties. We applied nonparametric methods, including multiple pairwise comparisons with a False Discovery Rate approach. Principal Component Analysis allowed the investigation of scattering of different factors (sex, weeks of feeding, diet, dose and group). Our analysis clearly reveals for the 3 GMOs new side effects linked with GM maize consumption, which were sex- and often dose-dependent. Effects were mostly associated with the kidney and liver, the dietary detoxifying organs, although different between the 3 GMOs. Other effects were also noticed in the heart, adrenal glands, spleen and haematopoietic system. We conclude that these data highlight signs of hepatorenal toxicity, possibly due to the new pesticides specific to each GM corn. In addition, unintended direct or indirect metabolic consequences of the genetic modification cannot be excluded.

  2. Cellular uptake and toxicity effects of silver nanoparticles in mammalian kidney cells.

    PubMed

    Milić, Mirta; Leitinger, Gerd; Pavičić, Ivan; Zebić Avdičević, Maja; Dobrović, Slaven; Goessler, Walter; Vinković Vrček, Ivana

    2015-06-01

    The rapid progress and early commercial acceptance of silver-based nanomaterials is owed to their biocidal activity. Besides embracing the antimicrobial potential of silver nanoparticles (AgNPs), it is imperative to give special attention to the potential adverse health effects of nanoparticles owing to prolonged exposure. Here, we report a detailed study on the in vitro interactions of citrate-coated AgNPs with porcine kidney (Pk15) cells. As uncertainty remains whether biological/cellular responses to AgNPs are solely as a result of the release of silver ions or whether the AgNPs themselves have toxic effects, we investigated the effects of Ag(+) on Pk15 cells for comparison. Next, we investigated the cellular uptake of both AgNPs and Ag(+) in Pk15 cells at various concentrations applied. The detected Ag contents in cells exposed to 50 mg l(-1) AgNPs and 50 mg l(-1) Ag(+) were 209 and 25 µg of Ag per 10(6) cells, respectively. Transmission electron microscopy (TEM) images indicated that the Pk15 cells internalized AgNPs by endocytosis. Both forms of silver, nano and ionic, decreased the number of viable Pk15 cells after 24 h in a dose-dependent manner. In spite of a significant uptake into the cells, AgNPs had only insignificant toxicity at concentrations lower than 25 mg l(-1) , whereas Ag(+) exhibited a significant decrease in cell viability at one-fifth of this concentration. The Comet assay suggested that a rather high concentration of AgNP (above 25 mg l(-1) ) is able to induce genotoxicity in Pk15 cells. Further studies must seek deeper understanding of AgNP behavior in biological media and their interactions with cellular membranes.

  3. The Effect of Periodontal Treatment on Hemoglobin A1c Levels of Diabetic Patients: A Systematic Review and Meta-Analysis

    PubMed Central

    Wang, Xingxing; Han, Xu; Guo, Xiaojing; Luo, Xiaolong; Wang, Dalin

    2014-01-01

    Background There is growing evidence that periodontal treatment may affect glycemic control in diabetic patients. And several systematic reviews have been conducted to assess the effect of periodontal treatment on diabetes outcomes. Researches of this aspect are widely concerned, and several new controlled trials have been published. The aim of this study was to update the account for recent findings. Methods A literature search (until the end of January 2014) was carried out using various databases with language restriction to English. A randomized controlled trial (RCT) was selected if it investigated periodontal therapy for diabetic subjects compared with a control group received no periodontal treatment for at least 3 months of the follow-up period. The primary outcome was hemoglobin A1c (HbA1c), and secondary outcomes were periodontal parameters included probing pocket depth (PPD) and clinical attachment level (CAL). Results Ten trials of 1135 patients were included in the analysis. After the follow-up of 3 months, treatment substantially lowered HbA1c compared with no treatment after periodontal therapy (–0.36%, 95%CI, −0.52% to −0.19%, P<0.0001). Clinically substantial and statistically significant reduction of PPD and CAL were found between subjects with and without treatment after periodontal therapy (PPD −0.42 mm, 95%CI: −0.60 to −0.23, P<0.00001; CAL −0.34 mm, 95%CI: −0.52 to −0.16, P = 0.0002). And there is no significant change of the level of HbA1c at the 6-month comparing with no treatment (–0.30%, 95%CI, −0.69% to 0.09%, P = 0.13). Conclusions Periodontal treatment leads to the modest reduction in HbA1c along with the improvement of periodontal status in diabetic patients for 3 months, and this result is consistent with previous systematic reviews. And the effect of periodontal treatment on HbA1c cannot be observed at 6-month after treatment. PMID:25255331

  4. Effect of the synthesis of rice non-symbiotic hemoglobins 1 and 2 in the recombinant Escherichia coli TB1 growth.

    PubMed

    Álvarez-Salgado, Emma; Arredondo-Peter, Raúl

    2015-01-01

    Non-symbiotic hemoglobins (nsHbs) are widely distributed in land plants, including rice. These proteins are classified into type 1 (nsHbs-1) and type 2. The O 2-affinity of nsHbs-1 is very high mostly because of an extremely low O 2-dissociation rate constant resulting in that nsHbs-1 apparently do not release O 2 after oxygenation. Thus, it is possible that the in vivo function of nsHbs-1 is other than O 2-transport. Based on the properties of multiple Hbs it was proposed that nsHbs-1 could play diverse roles in rice organs, however the in vivo activity of rice nsHbs-1 has been poorly analyzed. An in vivo analysis for rice nsHbs-1 is essential to elucidate the biological function(s) of these proteins. Rice Hb1 and Hb2 are nsHbs-1 that have been generated in recombinant Es cherichia coli TB1. The rice Hb1 and Hb2 amino acid sequence, tertiary structure and rate and equilibrium constants for the reaction of O 2 are highly similar. Thus, it is possible that rice Hb1 and Hb2 function similarly in vivo. As an initial approach to test this hypothesis we analyzed the effect of the synthesis of rice Hb1 and Hb2 in the recombinant E. coli TB1 growth. Effect of the synthesis of the O 2-carrying soybean leghemoglobin a, cowpea leghemoglobin II and Vitreoscilla Hb in the recombinant E. coli TB1 growth was also analyzed as an O 2-carrier control. Our results showed that synthesis of rice Hb1, rice Hb2, soybean Lb a, cowpea LbII and Vitreoscilla Hb inhibits the recombinant E. coli TB1 growth and that growth inhibition was stronger when recombinant E. coli TB1 synthesized rice Hb2 than when synthesized rice Hb1. These results suggested that rice Hb1 and Hb2 could function differently in vivo.

  5. Effect of the synthesis of rice non-symbiotic hemoglobins 1 and 2 in the recombinant Escherichia coli TB1 growth

    PubMed Central

    Álvarez-Salgado, Emma; Arredondo-Peter, Raúl

    2016-01-01

    Non-symbiotic hemoglobins (nsHbs) are widely distributed in land plants, including rice. These proteins are classified into type 1 (nsHbs-1) and type 2. The O 2-affinity of nsHbs-1 is very high mostly because of an extremely low O 2-dissociation rate constant resulting in that nsHbs-1 apparently do not release O 2 after oxygenation. Thus, it is possible that the in vivo function of nsHbs-1 is other than O 2-transport. Based on the properties of multiple Hbs it was proposed that nsHbs-1 could play diverse roles in rice organs, however the in vivo activity of rice nsHbs-1 has been poorly analyzed. An in vivo analysis for rice nsHbs-1 is essential to elucidate the biological function(s) of these proteins. Rice Hb1 and Hb2 are nsHbs-1 that have been generated in recombinant Es cherichia coli TB1. The rice Hb1 and Hb2 amino acid sequence, tertiary structure and rate and equilibrium constants for the reaction of O 2 are highly similar. Thus, it is possible that rice Hb1 and Hb2 function similarly in vivo. As an initial approach to test this hypothesis we analyzed the effect of the synthesis of rice Hb1 and Hb2 in the recombinant E. coli TB1 growth. Effect of the synthesis of the O 2-carrying soybean leghemoglobin a, cowpea leghemoglobin II and Vitreoscilla Hb in the recombinant E. coli TB1 growth was also analyzed as an O 2-carrier control. Our results showed that synthesis of rice Hb1, rice Hb2, soybean Lb a, cowpea LbII and Vitreoscilla Hb inhibits the recombinant E. coli TB1 growth and that growth inhibition was stronger when recombinant E. coli TB1 synthesized rice Hb2 than when synthesized rice Hb1. These results suggested that rice Hb1 and Hb2 could function differently in vivo. PMID:26973784

  6. The effect of optical substrates on micro-FTIR analysis of single mammalian cells.

    PubMed

    Wehbe, Katia; Filik, Jacob; Frogley, Mark D; Cinque, Gianfelice

    2013-02-01

    The study of individual cells with infrared (IR) microspectroscopy often requires living cells to be cultured directly onto a suitable substrate. The surface effect of the specific substrates on the cell growth-viability and associated biochemistry-as well as on the IR analysis-spectral interference and optical artifacts-is all too often ignored. Using the IR beamline, MIRIAM (Diamond Light Source, UK), we show the importance of the substrate used for IR absorption spectroscopy by analyzing two different cell lines cultured on a range of seven optical substrates in both transmission and reflection modes. First, cell viability measurements are made to determine the preferable substrates for normal cell growth. Successively, synchrotron radiation IR microspectroscopy is performed on the two cell lines to determine any genuine biochemically induced changes or optical effect in the spectra due to the different substrates. Multivariate analysis of spectral data is applied on each cell line to visualize the spectral changes. The results confirm the advantage of transmission measurements over reflection due to the absence of a strong optical standing wave artifact which amplifies the absorbance spectrum in the high wavenumber regions with respect to low wavenumbers in the mid-IR range. The transmission spectra reveal interference from a more subtle but significant optical artifact related to the reflection losses of the different substrate materials. This means that, for comparative studies of cell biochemistry by IR microspectroscopy, it is crucial that all samples are measured on the same substrate type.

  7. The antioxidant, cytotoxic, and antigenotoxic effects of galangin, puerarin, and ursolic acid in mammalian cells.

    PubMed

    Bacanlı, Merve; Başaran, A Ahmet; Başaran, Nurşen

    2016-07-27

    Phenolic compounds not only contribute to the sensory qualities of fruits and vegetables but also exhibit several health protective properties. Galangin, puerarin, and ursolic acid are commonly used plant phenolics in folk medicine. In this study, the antioxidant capacities of galangin, puerarin, and ursolic acid by the trolox equivalent antioxidant capacity (TEAC) assay and the cytotoxic effects by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in V79 cells were investigated. The genotoxic potentials of galangin, puerarin, and ursolic acid were evaluated by micronucleus (MN) and alkaline COMET assays in human lymphocytes and in V79 cells. Galangin, puerarin, and ursolic acid (10, 100, 500, 1000, 2000, 5000, 10 000, and 20 000 μM) were found to have antioxidant activities at the studied concentrations. IC50 values of galangin, puerarin, and ursolic acid in V79 cells were found to be 275.48 μM, 2503.712 μM, and 224.85 μM, respectively. Galangin, puerarin, and ursolic acid, at the all concentrations, have not exerted genotoxic effects and galangin, puerarin, and ursolic acid revealed a reduction in the frequency of MN and DNA damage induced by H2O2.

  8. Radiosensitizing effect of the histone acetyltransferase inhibitor anacardic acid on various mammalian cell lines

    PubMed Central

    CATE, ROSEMARIE TEN; KRAWCZYK, PRZEMEK; STAP, JAN; ATEN, JACOB A.; FRANKEN, NICOLAAS A.P.

    2010-01-01

    Agents that enhance the effectiveness of ionizing radiation have been investigated over many decades. A relatively new group of potential radiosensitizers consists of agents that inhibit histone acetyltransferases (HATs). This study evaluated the radiosensitizing properties of the HAT inhibitor anacardic acid (AA), used at a low-toxic concentration of 100 μM in V79, SW1573 and U2OS cells. Radiation survival curves were analyzed according to the linear quadratic model. Significant radiosensitization by AA was only obtained in U2OS cells. AA significantly increased the value of the linear parameter α, but not of the quadratic parameter β, indicating fixation of potentially lethal damage and an intact repair function of sublethal damage. The increase of the α value was also observed in SW1573 cells, but was not accompanied by a significant radiosensitization. A likely explanation for the enhancement of the α value may be an increase in the amount of lethal lesions due to the compacted chromatin structure. Despite the conflicting results of the radiosensitizing effect of AA in the three cell lines tested, the ability of AA to increase the α value suggests potential advantages for clinical application. PMID:22966377

  9. The Lack of Consistent Diaspirin Cross-Linked Hemoglobin Infusion Blood Pressure Effects in the US and EU Traumatic Hemorrhagic Shock Clinical Trials

    DTIC Science & Technology

    2009-04-01

    TRAUMATIC HEMORRHAGIC SHOCK CLINICAL TRIALS Edward P. Sloan,* Nora B. Philbin/ Max D. Koenigsberg,* Weihua Gao,§ and DCLHb Traumatic Hemorrhagic...hemorrhagic shock patients included two parallel Address reprint requests to Edward P. Sloan. MD, MPH, Department of Emergency Medicine, University of...human hemoglobin. Crit Care Med 28:2283-2292, 2000. 52. Cheng DC, Mazer CD, Martineau R, Ralph- Edwards A, Karski J, Robblee J, Finegan B, Hall RI

  10. The biology of mammalian parenting and its effect on offspring social development.

    PubMed

    Rilling, James K; Young, Larry J

    2014-08-15

    Parents know the transformative nature of having and caring for a child. Among many mammals, giving birth leads from an aversion to infant stimuli to irresistible attraction. Here, we review the biological mechanisms governing this shift in parental motivation in mammals. Estrogen and progesterone prepare the uterus for embryo implantation and placental development. Prolactin stimulates milk production, whereas oxytocin initiates labor and triggers milk ejection during nursing. These same molecules, interacting with dopamine, also activate specific neural pathways to motivate parents to nurture, bond with, and protect their offspring. Parenting in turn shapes the neural development of the infant social brain. Recent work suggests that many of the principles governing parental behavior and its effect on infant development are conserved from rodent to humans.

  11. The biology of mammalian parenting and its effect on offspring social development

    PubMed Central

    Rilling, James K.; Young, Larry J.

    2015-01-01

    Parents know the transformative nature of having and caring for a child. Among many mammals, giving birth leads from an aversion to infant stimuli to irresistible attraction. Here, we review the biological mechanisms governing this shift in parental motivation in mammals. Estrogen and progesterone prepare the uterus for embryo implantation and placental development. Prolactin stimulates milk production, whereas oxytocin initiates labor and triggers milk ejection during nursing. These same molecules, interacting with dopamine, also activate specific neural pathways to motivate parents to nurture, bond with, and protect their offspring. Parenting in turn shapes the neural development of the infant social brain. Recent work suggests that many of the principles governing parental behavior and its effect on infant development are conserved from rodent to humans. PMID:25124431

  12. Effects of exogenous amines on mammalian cells, with particular reference to membrane flow.

    PubMed Central

    Dean, R T; Jessup, W; Roberts, C R

    1984-01-01

    We have reviewed the evidence that amines accumulate in intracellular vesicles of low pH, such as lysosomes and endosomes. There is consequent elevation of intravesicular pH, and inhibition of receptor-ligand dissociation often results from this pH change. We have argued that the capacity for fusion of such vesicles is also reduced by the high pH. We suggest that the variety of effects of amines on membrane flow and macromolecular transport we describe are at least partly due to such reduced fusion (Figs. 1 and 2). We propose that an internal low pH may facilitate heterologous vesicle-vesicle and vesicle-plasma membrane fusion. There is some evidence that clathrin can accelerate phospholipid vesicle fusion in vitro at low pH (Blumenthal et al., 1983) but no direct evidence on the role of intravesicular pH. This idea is consistent not only with the preceding discussion, but also with the fact that the intracellular membrane-bound compartments least involved in fusion events (e.g. mitochondria) are of neutral or alkaline internal pH. Membrane fusion is certainly required for the formation of vesicles at the periphery of the Golgi apparatus, and possibly earlier in the transport and processing of biosynthetic products in the Golgi (Bergeron et al., 1982). Thus the accumulation of amines in the Golgi may be responsible for several effects on the flow of macromolecules along their translocation pathways. The status of the plasma membrane in this view is complex. It might be argued that the pH dictating the fusion step in endocytosis is that of the extracellular fluid, in which case the inhibitory effects of amines on this process are not explained. However, the rapidity of acidification of the newly formed endocytic vesicles allows the possibility that plasma membrane invaginations might temporarily sequester areas which are of lower pH than that of the bulk extracellular fluid even before fusion, since the proton pumping enzyme(s) are probably present on the plasma

  13. Effects of dietary phytophenols on the expression of microRNAs involved in mammalian cell homeostasis.

    PubMed

    Lançon, Allan; Michaille, Jean-Jacques; Latruffe, Norbert

    2013-10-01

    Besides synthesizing nutritive substances (proteins, fats and carbohydrates) for energy and growth, plants produce numerous non-energetic so-called secondary metabolites (mainly polyphenols) that allow them to protect themselves against infections and other types of hostile environments. Interestingly, these polyphenols often provide cells with valuable bioactive properties for the maintenance of their functions and homeostasis (signaling, gene regulation, protection against acquired or infectious diseases, etc.) both in humans and animals. Namely, from a nutritional point of view, and based on epidemiological data, it is now well accepted that the regular consumption of green vegetables, fruits and fibers has protective effects against the onset of cancer as well as of inflammatory, neurodegenerative, metabolic and cardiovascular diseases, and consequently increases the overall longevity. In particular, grapevine plants produce large amounts of a wide variety of polyphenols. The most prominent of those-resveratrol-has been shown to impair or delay cardiovascular alterations, cancer, inflammation, aging, etc. Until recently, the molecular bases of the pleiotropic effects of resveratrol remained largely unclear despite numerous studies on a variety of signaling pathways and the transcriptional networks that they control. However, it has been recently proposed that the protective properties of resveratrol may arise from its modulation of small non-coding regulatory RNAs, namely microRNAs. The aim of this review is to present up-to-date data on the control of microRNA expression by dietary phytophenols in different types of human cells, and their impact on cell differentiation, cancer development and the regulation of the inflammatory response.

  14. Carboxyalkylated Hemoglobin as a Potential Blood Substitute

    DTIC Science & Technology

    1989-09-20

    chromatography to remove minor and glycosylated hemoglobin components. Carbox) methylation Reaction - Many of the procedures have been described in our early...hemoglobin by peptide mapping after treatment with radiolabeled methyl acetyl phosphate. These binding sites are Met-l(3) and Lys-81(f) for liganded...ABSTRACT (Continue on reverse if necesary andia entify by block number) Carbox,, methylated hemoglobin is more stable than oxy hemoglobin during some

  15. Modelling antibiotic and cytotoxic isoquinoline effects in Staphylococcus aureus, Staphylococcus epidermidis and mammalian cells.

    PubMed

    Cecil, Alexander; Ohlsen, Knut; Menzel, Thomas; François, Patrice; Schrenzel, Jacques; Fischer, Adrien; Dörries, Kirsten; Selle, Martina; Lalk, Michael; Hantzschmann, Julia; Dittrich, Marcus; Liang, Chunguang; Bernhardt, Jörg; Ölschläger, Tobias A; Bringmann, Gerhard; Bruhn, Heike; Unger, Matthias; Ponte-Sucre, Alicia; Lehmann, Leane; Dandekar, Thomas

    2015-01-01

    Isoquinolines (IQs) are natural substances with an antibiotic potential we aim to optimize. Specifically, IQ-238 is a synthetic analog of the novel-type N,C-coupled naphthylisoquinoline (NIQ) alkaloid ancisheynine. Recently, we developed and tested other IQs such as IQ-143. By utilizing genome-wide gene expression data, metabolic network modelling and Voronoi tessalation based data analysis - as well as cytotoxicity measurements, chemical properties calculations and principal component analysis of the NIQs - we show that IQ-238 has strong antibiotic potential for staphylococci and low cytotoxicity against murine or human cells. Compared to IQ-143, systemic effects are less pronounced. Most enzyme activity changes due to IQ-238 are located in the carbohydrate metabolism. Validation includes metabolite measurements on biological replicates. IQ-238 delineates key properties and a chemical space for a good therapeutic window. The combination of analysis methods allows suggestions for further lead development and yields an in-depth look at staphylococcal adaptation and network changes after antibiosis. Results are compared to eukaryotic host cells.

  16. Novel insights in mammalian catalase heme maturation: effect of NO and thioredoxin-1.

    PubMed

    Chakravarti, Ritu; Gupta, Karishma; Majors, Alana; Ruple, Lisa; Aronica, Mark; Stuehr, Dennis J

    2015-05-01

    Catalase is a tetrameric heme-containing enzyme with essential antioxidant functions in biology. Multiple factors including nitric oxide (NO) have been shown to attenuate its activity. However, the possible impact of NO in relation to the maturation of active catalase, including its heme acquisition and tetramer formation, has not been investigated. We found that NO attenuates heme insertion into catalase in both short-term and long-term incubations. The NO inhibition in catalase heme incorporation was associated with defective oligomerization of catalase, such that inactive catalase monomers and dimers accumulated in place of the mature tetrameric enzyme. We also found that GAPDH plays a key role in mediating these NO effects on the structure and activity of catalase. Moreover, the NO sensitivity of catalase maturation could be altered up or down by manipulating the cellular expression level or activity of thioredoxin-1, a known protein-SNO denitrosylase enzyme. In a mouse model of allergic inflammatory asthma, we found that lungs from allergen-challenged mice contained a greater percentage of dimeric catalase relative to tetrameric catalase in the unchallenged control, suggesting that the mechanisms described here are in play in the allergic asthma model. Together, our study shows how maturation of active catalase can be influenced by NO, S-nitrosylated GAPDH, and thioredoxin-1, and how maturation may become compromised in inflammatory conditions such as asthma.

  17. Beyond the detergent effect: a binding site for sodium dodecyl sulfate (SDS) in mammalian apoferritin

    SciTech Connect

    Liu, Renyu Bu, Weiming; Xi, Jin; Mortazavi, Shirin R.; Cheung-Lau, Jasmina C.; Dmochowski, Ivan J.; Loll, Patrick J.

    2012-05-01

    Using X-ray crystallography and isothermal titration calorimetry, we show that sodium dodecyl sulfate (SDS) binds specifically to a pre-formed internal cavity in horse-spleen apoferritin. Although sodium dodecyl sulfate (SDS) is widely used as an anionic detergent, it can also exert specific pharmacological effects that are independent of the surfactant properties of the molecule. However, structural details of how proteins recognize SDS are scarce. Here, it is demonstrated that SDS binds specifically to a naturally occurring four-helix bundle protein: horse apoferritin. The X-ray crystal structure of the apoferritin–SDS complex was determined at a resolution of 1.9 Å and revealed that the SDS binds in an internal cavity that has previously been shown to recognize various general anesthetics. A dissociation constant of 24 ± 9 µM at 293 K was determined by isothermal titration calorimetry. SDS binds in this cavity by bending its alkyl tail into a horseshoe shape; the charged SDS head group lies in the opening of the cavity at the protein surface. This crystal structure provides insights into the protein–SDS interactions that give rise to binding and may prove useful in the design of novel SDS-like ligands for some proteins.

  18. Differential effects of temperature change and human impact on European Late Quaternary mammalian extinctions.

    PubMed

    Varela, Sara; Lima-Ribeiro, Matheus Souza; Diniz-Filho, José Alexandre Felizola; Storch, David

    2015-04-01

    Species that inhabited Europe during the Late Quaternary were impacted by temperature changes and early humans, resulting in the disappearance of half of the European large mammals. However, quantifying the relative importance that each factor had in the extinction risk of species has been challenging, mostly due to the spatio-temporal biases of fossil records, which complicate the calibration of realistic and accurate ecological niche modeling. Here, we overcome this problem by using ecotypes, and not real species, to run our models. We created 40 ecotypes with different temperature requirements (mean temperature from -20 °C to 25 °C and temperature range from 10 °C to 40 °C) and used them to quantify the effect of climate change and human impact. Our results show that cold-adapted ecotypes would have been highly affected by past temperature changes in Europe, whereas temperate and warm-adapted ecotypes would have been positively affected by temperature change. Human impact affected all ecotypes negatively, and temperate ecotypes suffered the greatest impacts. Based on these results, the extinction of cold-adapted species like Mammuthus primigenius may be related to temperature change, while the extinction of temperate species, like Crocuta crocuta, may be related to human impact. Our results suggest that temperature change and human impact affected different ecotypes in distinct ways, and that the interaction of both impacts may have shaped species extinctions in Europe.

  19. Stimulus and recording variables and their effects on mammalian vestibular evoked potentials

    NASA Technical Reports Server (NTRS)

    Jones, Sherri M.; Subramanian, Geetha; Avniel, Wilma; Guo, Yuqing; Burkard, Robert F.; Jones, Timothy A.

    2002-01-01

    Linear vestibular evoked potentials (VsEPs) measure the collective neural activity of the gravity receptor organs in the inner ear that respond to linear acceleration transients. The present study examined the effects of electrode placement, analog filtering, stimulus polarity and stimulus rate on linear VsEP thresholds, latencies and amplitudes recorded from mice. Two electrode-recording montages were evaluated, rostral (forebrain) to 'mastoid' and caudal (cerebellum) to 'mastoid'. VsEP thresholds and peak latencies were identical between the two recording sites; however, peak amplitudes were larger for the caudal recording montage. VsEPs were also affected by filtering. Results suggest optimum high pass filter cutoff at 100-300 Hz, and low pass filter cutoff at 10,000 Hz. To evaluate stimulus rate, linear jerk pulses were presented at 9.2, 16, 25, 40 and 80 Hz. At 80 Hz, mean latencies were longer (0.350-0.450 ms) and mean amplitudes reduced (0.8-1.8 microV) for all response peaks. In 50% of animals, late peaks (P3, N3) disappeared at 80 Hz. The results offer options for VsEP recording protocols. Copyright 2002 Elsevier Science B.V.

  20. The effects of the endocrine disruptors dithiocarbamates on the mammalian ovary with particular regard to mancozeb.

    PubMed

    Cecconi, Sandra; Paro, Rita; Rossi, Gianna; Macchiarelli, Guido

    2007-01-01

    Many human-made chemicals are called endocrine disruptors (EDs) because they have the potential to disrupt endocrine functions in exposed organisms. Many EDs can disrupt hormonal homeostasis by interfering with hormone receptor recognition, binding and activation, while others act by still unknown mechanisms. Among the EDs specifically affecting the female reproductive system, those with steroidogenic/antisteroidogenic effects have been extensively studied and the mechanisms of toxicity clarified also at molecular level. For many others, information is restricted to few epidemiological data and in vivo/in vitro experiments with animal models. This is the case of the dithiocarbamates, and in particular of the fungicide mancozeb, an ethylenedithiocarbamate widely used to protect fruit and vegetables, ginseng included, because of its low acute toxicity in humans. Although the mechanism(s) by which mancozeb may specifically act on female reproductive organs are largely unknown, data on experimental animals in vivo have demonstrated that the fungicide can induce several disturbances on estrus cycle. When used in vitro at concentrations considered too low to cause human health injuries, the fungicide impairs mouse embryo development and meiotic spindle assembly. The possibility that the female germ cell (the oocyte) could be a specific target of mancozeb suggests a role for this fungicide as probable inductor of infertility also in exposed human populations.

  1. The effect of diet on the mammalian gut flora and its metabolic activities.

    PubMed

    Rowland, I R; Mallett, A K; Wise, A

    1985-01-01

    The review will encompass the following points: A brief introduction to the role of the gut flora in the toxicology of ingested food components, contaminants, and additives, including known pathways of activation and detoxication of foreign compounds and the implication of the flora in enterohepatic circulation of xenobiotics. The advantages and disadvantages of the various methods of studying the gut flora (classical bacteriological techniques, metabolic and enzymological methods) will be critically discussed with special reference to their relevance to dietary, toxicological, and biochemical studies. Sources of nutrients available to the gut flora will be described including host products (mucus, sloughed mucosal cells, hormones, proteins) and exogenous nutrients derived from diet. An account of the problems involved in studies of dietary modification with special reference to the use of stock laboratory animal diets, purified diets, and human dietary studies. The influence of dietary modification on the flora will be assessed on the basis of changes in numbers and types of bacteria and their metabolic activity, drawing on data from human and animal studies. The effects of manipulation of the quantity and quality of protein, fat, and indigestible residues (fiber) of the diet will be described together with their possible implications for toxicity of ingested compounds.

  2. Intensive indoor versus outdoor swine production systems: genotype and supplemental iron effects on blood hemoglobin and selected immune measures in young pigs.

    PubMed

    Kleinbeck, S N; McGlone, J J

    1999-09-01

    The objectives of Exp. 1 were to determine the effects of production system and genotype on pig performance and health. Sows were bred, gestated, farrowed, and lactated in either an intensive indoor or an intensive outdoor production system. The three dam genotypes of pigs used in each environment were PIC Camborough-15 (C-15), PIC Camborough Blue (CB), and Yorkshire x Landrace (YL). All pigs received 100 mg of iron dextran at d 3 of age. Pigs raised in the outdoor unit had higher blood hemoglobin (Hb) concentrations on d 28 of age than pigs raised indoors (11.5 +/- .22 vs 8.16 +/- .26 g/dL, P < .0001). Outdoor-reared pigs had more white blood cells (WBC) on d 3 than indoor-reared pigs (9.7 +/- .38 vs 8.04 +/- .38 cells/microL x 10(3), P < .05), but outdoor pigs had fewer WBC on d 28 of age than indoor-reared pigs (9.8 +/- .5 vs 11.1 +/- .45 cells/microL x 10(3), P < .05). Genetic lines did not differ in plasma immunoglobulin G (IgG) concentrations at 3 or 28 d of age. Environment and age influenced pig Hb levels and WBC numbers. The objectives for Exp. 2 were to determine whether C-15-405 pigs reared outdoors or indoors needed supplemental iron or whether they would receive enough environmental iron, and how the lack of supplemental iron may impact pig Hb and immunity. Indoor and outdoor pigs received either no supplemental iron, 100 mg, or 400 mg of iron dextran on d 3 of age. Blood percentage neutrophils and neutrophil: lymphocyte ratio were lower (P < .05) indoors, and natural killer cell (NK) activity was greater (P < .05) among indoor- than outdoor-reared pigs (NK % cytotoxicity: 15.6 +/- 2.3 vs 9.7 +/- 2.3). Outdoor-reared pigs that received no injected iron had similar Hb at d 28 of age as indoor-reared pigs that received 100 mg of iron dextran (11.1 +/- .36 vs 10.7 +/- .4 g/dL, P = .59). Supplemental iron may not be necessary in an outdoor production system. Outdoor-reared pigs had lower values for some immune measures, but they had similar survival rates

  3. Visualizing the Bohr effect in hemoglobin: neutron structure of equine cyanomethemoglobin in the R state and comparison with human deoxyhemoglobin in the T state

    PubMed Central

    Dajnowicz, Steven; Seaver, Sean; Hanson, B. Leif; Fisher, S. Zoë; Langan, Paul; Kovalevsky, Andrey Y.; Mueser, Timothy C.

    2016-01-01

    Neutron crystallography provides direct visual evidence of the atomic positions of deuterium-exchanged H atoms, enabling the accurate determination of the protonation/deuteration state of hydrated biomolecules. Comparison of two neutron structures of hemoglobins, human deoxyhemoglobin (T state) and equine cyanomethemoglobin (R state), offers a direct observation of histidine residues that are likely to contribute to the Bohr effect. Previous studies have shown that the T-state N-terminal and C-terminal salt bridges appear to have a partial instead of a primary overall contribution. Four conserved histidine residues [αHis72(EF1), αHis103(G10), αHis89(FG1), αHis112(G19) and βHis97(FG4)] can become protonated/deuterated from the R to the T state, while two histidine residues [αHis20(B1) and βHis117(G19)] can lose a proton/deuteron. αHis103(G10), located in the α1:β1 dimer interface, appears to be a Bohr group that undergoes structural changes: in the R state it is singly protonated/deuterated and hydrogen-bonded through a water network to βAsn108(G10) and in the T state it is doubly protonated/deuterated with the network uncoupled. The very long-term H/D exchange of the amide protons identifies regions that are accessible to exchange as well as regions that are impermeable to exchange. The liganded relaxed state (R state) has comparable levels of exchange (17.1% non-exchanged) compared with the deoxy tense state (T state; 11.8% non-exchanged). Interestingly, the regions of non-exchanged protons shift from the tetramer interfaces in the T-state interface (α1:β2 and α2:β1) to the cores of the individual monomers and to the dimer interfaces (α1:β1 and α2:β2) in the R state. The comparison of regions of stability in the two states allows a visualization of the conservation of fold energy necessary for ligand binding and release. PMID:27377386

  4. Mutagenic effects of a single and an exact number of alpha particles in mammalian cells

    NASA Technical Reports Server (NTRS)

    Hei, T. K.; Wu, L. J.; Liu, S. X.; Vannais, D.; Waldren, C. A.; Randers-Pehrson, G.

    1997-01-01

    One of the main uncertainties in risk estimation for environmental radon exposure using lung cancer data from underground miners is the extrapolation from high- to low-dose exposure where multiple traversal is extremely rare. The biological effects of a single alpha particle are currently unknown. Using the recently available microbeam source at the Radiological Research Accelerator Facility at Columbia University, we examined the frequencies and molecular spectrum of S1- mutants induced in human-hamster hybrid (A(L)) cells by either a single or an exact number of alpha particles. Exponentially growing cells were stained briefly with a nontoxic concentration of Hoechst dye for image analysis, and the location of individual cells was computer-monitored. The nucleus of each cell was irradiated with either 1,2,4, or 8 alpha particles at a linear energy transfer of 90 keV/microm consistent with the energy spectrum of domestic radon exposure. Although single-particle traversal was only slightly cytotoxic to A(L) cells (survival fraction approximately 0.82), it was highly mutagenic, and the induced mutant fraction averaged 110 mutants per 10(5) survivors. In addition, both toxicity and mutant induction were dose-dependent. Multiplex PCR analysis of mutant DNA showed that the proportion of mutants with multilocus deletions increased with the number of particle traversals. These data provide direct evidence that a single a particle traversing a nucleus will have a high probability of resulting in a mutation and highlight the need for radiation protection at low doses.

  5. Mutagenic effects of a single and an exact number of alpha particles in mammalian cells.

    PubMed

    Hei, T K; Wu, L J; Liu, S X; Vannais, D; Waldren, C A; Randers-Pehrson, G

    1997-04-15

    One of the main uncertainties in risk estimation for environmental radon exposure using lung cancer data from underground miners is the extrapolation from high- to low-dose exposure where multiple traversal is extremely rare. The biological effects of a single alpha particle are currently unknown. Using the recently available microbeam source at the Radiological Research Accelerator Facility at Columbia University, we examined the frequencies and molecular spectrum of S1- mutants induced in human-hamster hybrid (A(L)) cells by either a single or an exact number of alpha particles. Exponentially growing cells were stained briefly with a nontoxic concentration of Hoechst dye for image analysis, and the location of individual cells was computer-monitored. The nucleus of each cell was irradiated with either 1,2,4, or 8 alpha particles at a linear energy transfer of 90 keV/microm consistent with the energy spectrum of domestic radon exposure. Although single-particle traversal was only slightly cytotoxic to A(L) cells (survival fraction approximately 0.82), it was highly mutagenic, and the induced mutant fraction averaged 110 mutants per 10(5) survivors. In addition, both toxicity and mutant induction were dose-dependent. Multiplex PCR analysis of mutant DNA showed that the proportion of mutants with multilocus deletions increased with the number of particle traversals. These data provide direct evidence that a single a particle traversing a nucleus will have a high probability of resulting in a mutation and highlight the need for radiation protection at low doses.

  6. Blood Test: Hemoglobin A1C

    MedlinePlus

    ... Your 1- to 2-Year-Old Blood Test: Hemoglobin A1c KidsHealth > For Parents > Blood Test: Hemoglobin A1c A A A What's in this article? ... de sangre: hemoglobina A1c What It Is A hemoglobin A1c (HbA1c) test is used to monitor long- ...

  7. Hemoglobin C Trait Provides Protection From Clinical Falciparum Malaria in Malian Children

    PubMed Central

    Travassos, Mark A.; Coulibaly, Drissa; Laurens, Matthew B.; Dembélé, Ahmadou; Tolo, Youssouf; Koné, Abdoulaye K.; Traoré, Karim; Niangaly, Amadou; Guindo, Aldiouma; Wu, Yukun; Berry, Andrea A.; Jacob, Christopher G.; Takala-Harrison, Shannon; Adams, Matthew; Shrestha, Biraj; Mu, Amy Z.; Kouriba, Bourema; Lyke, Kirsten E.; Diallo, Dapa A.; Doumbo, Ogobara K.; Plowe, Christopher V.; Thera, Mahamadou A.

    2015-01-01

    Background. Hemoglobin C trait, like hemoglobin S trait, protects against severe malaria in children, but it is unclear whether hemoglobin C trait also protects against uncomplicated malaria. We hypothesized that Malian children with hemoglobin C trait would have a lower risk of clinical malaria than children with hemoglobin AA. Methods. Three hundred children aged 0–6 years were enrolled in a cohort study of malaria incidence in Bandiagara, Mali, with continuous passive and monthly active follow-up from June 2009 to June 2010. Results. Compared to hemoglobin AA children (n = 242), hemoglobin AC children (n = 39) had a longer time to first clinical malaria episode (hazard ratio [HR], 0.19; P = .001; 364 median malaria-free days vs 181 days), fewer episodes of clinical malaria, and a lower cumulative parasite burden. Similarly, hemoglobin AS children (n = 14) had a longer time to first clinical malaria episode than hemoglobin AA children (HR, 0.15; P = .015; 364 median malaria-free days vs 181 days), but experienced the most asymptomatic malaria infections of any group. Conclusions. Both hemoglobin C and S traits exerted a protective effect against clinical malaria episodes, but appeared to do so by mechanisms that differentially affect the response to infecting malaria parasites. PMID:26019283

  8. Rodent Habitat on ISS: Advances in Capability for Determining Spaceflight Effects on Mammalian Physiology

    NASA Technical Reports Server (NTRS)

    Globus, R. K.; Choi, S.; Gong, C.; Leveson-Gower, D.; Ronca, A.; Taylor, E.; Beegle, J.

    2016-01-01

    -flight showed that there were no differences between FLT and GC groups in adrenal gland and spleen weights, whereas FLT thymus and liver weights exceeded those of GC. Minimal differences between the control groups (GC and VIV) were observed. In addition, Over 3,000 aliquots collected post-flight from the four groups of mice were deposited into the Ames Life Science Data Archives for the Biospecimen Sharing Program and Genelab project. New capabilities recently developed include DEXA scanning, grip strength tests and male mice. In conclusion, new capability for long duration rodent habitation of group-housed rodents was developed and includes in-flight sample collection, thus avoiding the complication of reentry. Results obtained to date reveal the possibility of striking differences between the effects of short duration vs. long duration spaceflight. This Rodent Research system enables achievement of both basic science and translational research objectives to advance human exploration of space.

  9. The inotropic effect of nitric oxide on mammalian papillary muscle is dependent on the level of beta1-adrenergic stimulation.

    PubMed

    Reading, S A; Barclay, J K

    2002-06-01

    We tested the hypothesis that nitric oxide has a positive inotropic effect on mammalian cardiac muscle contractility and that this effect sums with the positive inotropic effect of beta1-adrenergic agonists when both are present. Feline right ventricular papillary muscles were stimulated to contract isometrically at 0.2 Hz in Krebs-Henseleit bicarbonate buffer (KREBS) gassed with 95% O2 and 5% CO2 (26 degrees C; pH 7.34). The nitric oxide (NO) donor, S-nitroso-N-acetylpenicillamine (SNAP, 10(-5) M), and the membrane permeable cGMP analog 8-bromoguanosine-3',5'-cyclophosphate sodium (Br-cGMP, 10(-5) M), significantly increased developed force by 13.3+/-1.5% (n = 11) and 7.8+/-2.8% (n = 7), respectively. SNAP, at 10(-5) M, significantly increased the force developed by papillary muscle treated with 10(-11) M or 10(-9) M dobutamine hydrochloride (a beta1-adrenergic agonist) (n = 25, 11.3+/-2.9% and 10.0+/-3.6%, respectively) when compared with the addition of KREBS (n = 27, 2.6+/-0.9% and 5.5+/-0.9%), but the increase was less than predicted by the sum of inotropic effects of SNAP and dobutamine. SNAP at 10(-5) M did not change developed force in muscles treated with 10(-7) M dobutamine but it significantly decreased developed force in muscles challenged with 10(-5) M dobutamine (n = 18, 29.3+/-5.0%) when compared with KREBS (n = 10, 41.5+/-6.8%). Similarly, 10(-4) M 8-bromo-adenosine cyclic 3',5'-hydrogen phosphate monosodium (a membrane permeable cAMP analog) increased developed force 14.9+/-3.3% and the addition of 10(-5) M Br-cGMP to those muscles significantly reduced developed force by 3.5%+/-1.1% (n = 7). Thus, the positive inotropic effect of NO decreased and ultimately became an attenuation as the level of beta1-adrenergic stimulation increased due at least in part, to an interaction between the cAMP and cGMP second messenger pathways.

  10. Mutant quantity and quality in mammalian cells (A{sub L}) exposed to cesium-137 gamma radiation: Effect of caffeine

    SciTech Connect

    McGuinness, S.M.; Shibuya, M.L.; Ueno, A.M.

    1995-06-01

    We examined the effect of caffeine (1,3,7-trimethylxanthine) on the quantity and quality of mutations in cultured mammalian A{sub L} human-hamster hybrid cells exposed to {sup 137}Cs {gamma} radiation. At a dose (1.5 mg/ml for 16 h) that reduced the plating efficiency (PE) by 20%, caffeine was not itself a significant mutagen, but it increased by approximately twofold the slope of the dose-response curve for induction of S1{sup {minus}} mutants by {sup 137}Cs {gamma} radiation. Molecular analysis of 235 S1{sup {minus}} mutants using a series of DNA probes mapped to the human chromosome 11 in the A{sub L} hybrid cells revealed that 73 to 85% of the mutations in unexposed cells and in cells treated with caffeine alone, {sup 137}Cs {gamma} rays alone or {sup 137}Cs {gamma} rays plus caffeine were large deletions involving millions of base pairs of DNA. Most of these deletions were contiguous with the region of the MIC1 gene at 11p13 that encodes the S1 cell surface antigen. In other mutants that had suffered multiple marker loss, the deletions were intermittent along chromosome 11. These {open_quotes}complex{close_quotes} mutations were rare for {sup 137}Cs {gamma} irradiation (1/63 = 1.5%) but relatively prevalent (23-50%) for other exposure conditions. Thus caffeine appears to alter both the quantity and quality of mutations induced by {sup 137}Cs {gamma} irradiation. 62 refs., 3 figs., 3 tabs.

  11. Lineweaver-Burk analysis for the blocking effects of mammalian dopamine receptor antagonists on dopamine-induced currents in Achatina giant neurones.

    PubMed

    Emaduddin, M; Takeuchi, H

    1996-10-01

    1. We had demonstrated (Emaduddin et al., 1995) the blocking effects of the three mammalian dopamine receptor antagonists, (+/-)-SKF83566 (mammalian dopamine D1-like receptor antagonist), (+)-UH232 (D2 and D3-like receptor antagonist) and (+/-)-sulpiride (D2-like receptor antagonist) on the dose (pressure duration)-response curves of dopamine in the three giant neurone types, LVMN (left visceral multiple spike neurone), d-RPeAN (dorsal-right pedal anterior neurone) and v-LCDN (ventral-left cerebral distinct neurone), of Achatina fulica Férussac under voltage clamp. In the present study, we analyzed these data by Lineweaver-Burk plot. 2. Dopamine-induced inward currents (Iin) of the two neurone types, LVMN and d-RPeAN, were blocked by (+/-)-SKF83566 and (+)-UH232 in partly noncompetitive and partly uncompetitive manners. (+/-)-Sulpiride had no effect on these currents. 3. In contrast, dopamine-induced outward current (Iout) of v-LCDN was inhibited competitively by (+/-)-sulpiride and noncompetitively by (+)-UH232. (+/-)-SKF83566 had no effect on this current. 4. Therefore, we consider that the pharmacological features of the dopamine receptors of Achatina neurones are not identical in detail to those of the mammalian dopamine receptors.

  12. 17β-Hydroxyestra-4,9,11-trien-3-one (trenbolone) exhibits tissue selective anabolic activity: effects on muscle, bone, adiposity, hemoglobin, and prostate.

    PubMed

    Yarrow, Joshua F; Conover, Christine F; McCoy, Sean C; Lipinska, Judyta A; Santillana, Cesar A; Hance, John M; Cannady, Darryl F; VanPelt, Tisha D; Sanchez, Joshua; Conrad, Bryan P; Pingel, Jennifer E; Wronski, Thomas J; Borst, Stephen E

    2011-04-01

    Selective androgen receptor modulators (SARMs) now under development can protect against muscle and bone loss without causing prostate growth or polycythemia. 17β-Hydroxyestra-4,9,11-trien-3-one (trenbolone), a potent testosterone analog, may have SARM-like actions because, unlike testosterone, trenbolone does not undergo tissue-specific 5α-reduction to form more potent androgens. We tested the hypothesis that trenbolone-enanthate (TREN) might prevent orchiectomy-induced losses in muscle and bone and visceral fat accumulation without increasing prostate mass or resulting in adverse hemoglobin elevations. Male F344 rats aged 3 mo underwent orchiectomy or remained intact and were administered graded doses of TREN, supraphysiological testosterone-enanthate, or vehicle for 29 days. In both intact and orchiectomized animals, all TREN doses and supraphysiological testosterone-enanthate augmented androgen-sensitive levator ani/bulbocavernosus muscle mass by 35-40% above shams (P ≤ 0.001) and produced a dose-dependent partial protection against orchiectomy-induced total and trabecular bone mineral density losses (P < 0.05) and visceral fat accumulation (P < 0.05). The lowest doses of TREN successfully maintained prostate mass and hemoglobin concentrations at sham levels in both intact and orchiectomized animals, whereas supraphysiological testosterone-enanthate and high-dose TREN elevated prostate mass by 84 and 68%, respectively (P < 0.01). In summary, low-dose administration of the non-5α-reducible androgen TREN maintains prostate mass and hemoglobin concentrations near the level of shams while producing potent myotrophic actions in skeletal muscle and partial protection against orchiectomy-induced bone loss and visceral fat accumulation. Our findings indicate that TREN has advantages over supraphysiological testosterone and supports the need for future preclinical studies examining the viability of TREN as an option for androgen replacement therapy.

  13. Effect of neohesperidin dihydrochalcone on the activity and stability of alpha-amylase: a comparative study on bacterial, fungal, and mammalian enzymes.

    PubMed

    Kashani-Amin, Elaheh; Ebrahim-Habibi, Azadeh; Larijani, Bagher; Moosavi-Movahedi, Ali Akbar

    2015-10-01

    Neohesperidin dihydrochalcone (NHDC) was recently introduced as an activator of mammalian alpha-amylase. In the current study, the effect of NHDC has been investigated on bacterial and fungal alpha-amylases. Enzyme assays and kinetic analysis demonstrated the capability of NHDC to significantly activate both tested alpha-amylases. The ligand activation pattern was found to be more similar between the fungal and mammalian enzyme in comparison with the bacterial one. Further, thermostability experiments indicated a stability increase in the presence of NHDC for the bacterial enzyme. In silico (docking) test locates a putative binding site for NHDC on alpha-amylase surface in domain B. This domain shows differences in various alpha-amylase types, and the different behavior of the ligand toward the studied enzymes may be attributed to this fact.

  14. Structural transition temperature of hemoglobins correlates with species' body temperature.

    PubMed

    Zerlin, Kay Frank Thorsten; Kasischke, Nicole; Digel, Ilya; Maggakis-Kelemen, Christina; Temiz Artmann, Aysegül; Porst, Dariusz; Kayser, Peter; Linder, Peter; Artmann, Gerhard Michael

    2007-12-01

    Human red blood cells (RBCs) exhibit sudden changes in their biophysical properties at body temperature (T (B)). RBCs were seen to undergo a spontaneous transition from blockage to passage at T (C) = 36.4 +/- 0.3 degrees C, when the temperature dependency of RBC-passages through 1.3 mum narrow micropipettes was observed. Moreover, concentrated hemoglobin solutions (45 g/dl) showed a viscosity breakdown between 36 and 37 degrees C. With human hemoglobin, a structural transition was observed at T (B) as circular dichroism (CD) experiments revealed. This leads to the assumption that a species' body temperature occupies a unique position on the temperature scale and may even be imprinted in the structure of certain proteins. In this study, it was investigated whether hemoglobins of species with a T (B) different from those of human show temperature transitions and whether those were also linked to the species' T (B). The main conclusion was drawn from dynamic light scattering (DLS) and CD experiments. It was observed that such structural temperature transitions did occur in hemoglobins from all studied species and were correlated linearly (slope 0.81, r = 0.95) with the species' body temperature. We presumed that alpha-helices of hemoglobin were able to unfold more readily around T (B). alpha-helical unfolding would initiate molecular aggregation causing RBC passage and viscosity breakdown as mentioned above. Thus, structural molecular changes of hemoglobin could determine biophysical effects visible on a macroscopic scale. It is hypothesized that the species' body temperature was imprinted into the structure of hemoglobins.

  15. Synergistic Effect of S224P and N383D Substitutions in the PA of H5N1 Avian Influenza Virus Contributes to Mammalian Adaptation.

    PubMed

    Song, Jiasheng; Xu, Jing; Shi, Jianzhong; Li, Yanbing; Chen, Hualan

    2015-05-22

    The adaptation of H5N1 avian influenza viruses to human poses a great threat to public health. Previous studies indicate the adaptive mutations in viral polymerase of avian influenza viruses are major contributors in overcoming the host species barrier, with the majority of mammalian adaptive mutations occurring in the PB2 protein. However, the adaptive mutations in the PA protein of the H5N1 avian influenza virus are less defined and poorly understood. In this study, we identified the synergistic effect of the PA/224P + 383D of H5N1 avian influenza viruses and its ability to enhance the pathogenicity and viral replication in a mammalian mouse model. Interestingly, the signature of PA/224P + 383D mainly exists in mammalian isolates of the H5N1 influenza virus and pdmH1N1 influenza virus, providing a potential pathway for the natural adaptation to mammals which imply the effects of natural adaptation to mammals. Notably, the mutation of PA/383D, which is highly conserved in avian influenza viruses, increases the polymerase activity in both avian and human cells, and may have roles in maintaining the avian influenza virus in their avian reservoirs, and jumping species to infect humans.

  16. Long-Term Single and Joint Effects of Excessive Daytime Napping on the HOMA-IR Index and Glycosylated Hemoglobin: A Prospective Cohort Study.

    PubMed

    Li, Xue; Pang, Xiuyu; Zhang, Qiao; Qu, Qiannuo; Hou, Zhigang; Liu, Zhipeng; Lv, Lin; Na, Guanqiong; Zhang, Wei; Sun, Changhao; Li, Ying

    2016-02-01

    This prospective cohort study was conducted to assess the duration of daytime napping and its effect combined with night sleep deprivation on the risk of developing high HOMA-IR (homeostasis model assessment of insulin resistance) index and disadvantageous changes in glycosylated hemoglobin (HbA1c) levels.A total of 5845 diabetes-free subjects (2736 women and 3109 men), 30 to 65 years of age, were targeted for this cohort study since 2008. Multiple adjusted Cox regression models were performed to evaluate the single and joint effects of daytime napping on the risk of an elevated HbA1c level and high HOMA-IR index.After an average of 4.5 years of follow-up, >30 minutes of daytime napping was significantly associated with an increased risk of an elevated HbA1c level (>6.5%) in men and women (all P trend < 0.05). Hazard ratios (HRs) for an HbA1c level between 5.7% and 6.4% were also significant in the entire cohort and women, but nonsignificant in men. HRs (95% confidence interval, CIs) for the high HOMA-IR index in the entire cohort, men, and women were 1.33 (1.10-1.62), 1.46 (1.08-1.98), and 1.47 (1.12-1.91), respectively. The combination of sleep deprivation with no naps or >30 minutes napping and the combination of no sleep deprivation with >30 minutes daytime napping were all associated with an HbA1c level >6.5% (HR = 2.08, 95% CI = 1.24-3.51; HR = 4.00, 95% CI = 2.03-7.90; and HR = 2.05, 95% CI = 1.29-3.27, respectively). No sleep deprivation combined with >30 minutes daytime napping correlated with a high risk of an HbA1c level between 5.7% and 6.4% and high HOMA-IR index (HR = 2.12, 95% CI = 1.48-3.02; and HR = 1.35, 95% CI = 1.10-1.65, respectively).Daytime napping >30 minutes was associated with a high risk of an elevated HbA1c level and high HOMA-IR index. No sleep deprivation combined with napping >30 minutes carries a risk of abnormal glucose metabolism. Sleep deprivation combined with brief daytime napping <30

  17. Hemoglobin allostery: new views on old players.

    PubMed

    Miele, Adriana Erica; Bellelli, Andrea; Brunori, Maurizio

    2013-05-13

    Proteins are dynamic molecular machines whose structure and function are modulated by environmental perturbations and natural selection. Allosteric regulation, discovered in 1963 as a novel molecular mechanism of enzymatic adaptation [Monod, Changeux & Jacob (1963). J. Mol. Biol.6, 306-329], seems to be the leit motiv of enzymes and metabolic pathways, enabling fine and quick responses toward external perturbations. Hemoglobin (Hb), the oxygen transporter of all vertebrates, has been for decades the paradigmatic system to test the validity of the conformational selection mechanism, the conceptual innovation introduced by Monod, Wyman and Changeux. We present hereby the results of a comparative analysis of structure, function and thermodynamics of two extensively investigated hemoglobins: human HbA and trout HbI. They represent a unique and challenging comparison to test the general validity of the stereochemical model proposed by Perutz. Indeed both proteins are ideal for the purpose being very similar yet very different. In fact, T-HbI is a low-ligand-affinity cooperative tetrameric Hb, insensitive to all allosteric effectors. This remarkable feature, besides being physiologically sound, supports the stereochemical model, given that the six residues identified in HbA as responsible for the Bohr and the 2,3-di-phosphoglycerate effects are all mutated. Comparison of the three-dimensional structures of HbA and T-HbI allows unveiling the molecular mechanism whereby the latter has a lower O2 affinity. Moreover, the energetic balance sheet shows that the salt bridges breaking upon allosteric quaternary transition are important yet insufficient to account for the free energy of heme-heme interactions in both hemoglobins.

  18. The Effect of 5α-Reductase Inhibition With Dutasteride and Finasteride on Bone Mineral Density, Serum Lipoproteins, Hemoglobin, Prostate Specific Antigen and Sexual Function in Healthy Young Men

    PubMed Central

    Amory, John K.; Anawalt, Bradley D.; Matsumoto, Alvin M.; Page, Stephanie T.; Bremner, William J.; Wang, Christina; Swerdloff, Ronald S.; Clark, Richard V.

    2009-01-01

    Purpose Dutasteride and finasteride are 5α-reductase inhibitors that dramatically decrease serum levels of dihydrotestosterone. Because androgens affect bone, lipids, hematopoiesis, prostate and sexual function, we determined the impact of 5α-reductase inhibitors on these end points. Materials and Methods We conducted a randomized, double-blinded, placebo controlled trial of 99 men 18 to 55 years old randomly assigned to receive 0.5 mg dutasteride (33), 5 mg finasteride (34) or placebo (32) daily for 1 year. Bone mineral density was measured at baseline, after 1 year of treatment and 6 months after drug discontinuation. In addition, markers of bone turnover, fasting serum lipoprotein concentrations, hemoglobin and prostate specific antigen were measured at baseline, after 26 and 52 weeks of treatment, and again 24 weeks after drug discontinuation. Sexual function was assessed at these points by a validated questionnaire. Results Significant suppression of circulating dihydrotestosterone levels with the administration of dutasteride or finasteride did not significantly affect bone mineral density or markers of bone metabolism. Similarly serum lipoproteins and hemoglobin were unaffected. Serum prostate specific antigen and self-assessed sexual function decreased slightly during treatment with both 5α-reductase inhibitors but returned to baseline during followup. Conclusions Profound suppression of circulating serum dihydrotestosterone induced by 5α-reductase inhibitors during 1 year does not adversely impact bone, serum lipoproteins or hemoglobin, and has a minimal, reversible effect on serum prostate specific antigen and sexual function in normal men. Circulating dihydrotestosterone does not appear to have a clinically significant role in modulating bone mass, hematopoiesis or lipid metabolism in normal men. PMID:18423697

  19. Insights into Hemoglobin Assembly through in Vivo Mutagenesis of α-Hemoglobin Stabilizing Protein*

    PubMed Central

    Khandros, Eugene; Mollan, Todd L.; Yu, Xiang; Wang, Xiaomei; Yao, Yu; D'Souza, Janine; Gell, David A.; Olson, John S.; Weiss, Mitchell J.

    2012-01-01

    α-Hemoglobin stabilizing protein (AHSP) is believed to facilitate adult Hemoglobin A assembly and protect against toxic free α-globin subunits. Recombinant AHSP binds multiple forms of free α-globin to stabilize their structures and inhibit precipitation. However, AHSP also stimulates autooxidation of αO2 subunit and its rapid conversion to a partially unfolded bishistidyl hemichrome structure. To investigate these biochemical properties, we altered the evolutionarily conserved AHSP proline 30 in recombinantly expressed proteins and introduced identical mutations into the endogenous murine Ahsp gene. In vitro, the P30W AHSP variant bound oxygenated α chains with 30-fold increased affinity. Both P30W and P30A mutant proteins also caused decreased rates of αO2 autooxidation as compared with wild-type AHSP. Despite these abnormalities, mice harboring P30A or P30W Ahsp mutations exhibited no detectable defects in erythropoiesis at steady state or during induced stresses. Further biochemical studies revealed that the AHSP P30A and P30W substitutions had minimal effects on AHSP interactions with ferric α subunits. Together, our findings indicate that the ability of AHSP to stabilize nascent α chain folding intermediates prior to hemin reduction and incorporation into adult Hemoglobin A is physiologically more important than AHSP interactions with ferrous αO2 subunits. PMID:22287545

  20. Effects of deletion of the ac109 gene of Autographa californica nucleopolyhedrovirus on interactions with mammalian cells.

    PubMed

    Alfonso, Victoria; Amalfi, Sabrina; López, María Gabriela; Taboga, Oscar

    2017-03-01

    Baculoviruses are able to enter into mammalian cells, where they can express a transgene that is placed under an appropriate promoter, without producing infectious progeny. ORF109 encodes an essential baculovirus protein that participates in the interaction of the baculovirus with mammalian cells. To date, the mechanisms underlying this interaction are not yet known. We demonstrated that although a Ac109 knock out virus maintained its ability to enter into BHK-21 cells, there was a marked reduction in the expression efficiency of the nuclear transgene. Moreover, the amount of free cytoplasmic viral DNA, which was detected by transcription of a reporter gene, was severely diminished. These results suggest Ac109 could be involved in maintaining the integrity of the viral nucleic acid.

  1. Broadband diffuse optical spectroscopy assessment of hemorrhage- and hemoglobin-based blood substitute resuscitation.

    PubMed

    Lee, Jangwoen; Kim, Jae G; Mahon, Sari; Tromberg, Bruce J; Mukai, David; Kreuter, Kelly; Saltzman, Darin; Patino, Renee; Goldberg, Robert; Brenner, Matthew

    2009-01-01

    Hemoglobin-based oxygen carriers (HBOCs) are solutions of cell-free hemoglobin (Hb) that have been developed for replacement or augmentation of blood transfusion. It is important to monitor in vivo tissue hemoglobin content, total tissue hemoglobin [THb], oxy- and deoxy-hemoglobin concentrations ([OHb], [RHb]), and tissue oxygen saturation (S(t)O(2)=[OHb][THb]x100%) to evaluate effectiveness of HBOC transfusion. We designed and constructed a broadband diffuse optical spectroscopy (DOS) prototype system to measure bulk tissue absorption and scattering spectra between 650 and 1000 nm capable of accurately determining these tissue hemoglobin component concentrations in vivo. Our purpose was to assess the feasibility of using DOS to optically monitor tissue [OHb], [RHb], S(t)O(2), and total tissue hemoglobin concentration ([THb]=[OHb]+[RHb]) during HBOC infusion using a rabbit hypovolemic shock model. The DOS prototype probe was placed on the shaved inner thigh muscle of the hind leg to assess concentrations of [OHb], [RHb], [THb], as well as S(t)O(2). Hemorrhagic shock was induced in intubated New Zealand white rabbits (N=6) by withdrawing blood via a femoral arterial line to 20% blood loss (10-15 cckg). Hemoglobin glutamer-200 (Hb-200) 1:1 volume resuscitation was administered following the hemorrhage. These values were compared against traditional invasive measurements, serum hemoglobin concentration (sHGB), systemic blood pressure, heart rate, and blood gases. DOS revealed increases of [THb], [OHb], and tissue hemoglobin oxygen saturation after Hb-200 infusion, while blood total hemoglobin values continued did not increase; we speculate, due to hyperosmolality induced hemodilution. DOS enables noninvasive in vivo monitoring of tissue hemoglobin and oxygenation parameters during shock and volume expansion with HBOC and potentially enables the assessment of efficacy of resuscitation efforts using artificial blood substitutes.

  2. Broadband diffuse optical spectroscopy assessment of hemorrhage- and hemoglobin-based blood substitute resuscitation

    NASA Astrophysics Data System (ADS)

    Lee, Jangwoen; Kim, Jae G.; Mahon, Sari; Tromberg, Bruce J.; Mukai, David; Kreuter, Kelly; Saltzman, Darin; Patino, Renee; Goldberg, Robert; Brenner, Matthew

    2009-07-01

    Hemoglobin-based oxygen carriers (HBOCs) are solutions of cell-free hemoglobin (Hb) that have been developed for replacement or augmentation of blood transfusion. It is important to monitor in vivo tissue hemoglobin content, total tissue hemoglobin [THb], oxy- and deoxy-hemoglobin concentrations ([OHb], [RHb]), and tissue oxygen saturation (StO2=[OHb]/[THb]×100%) to evaluate effectiveness of HBOC transfusion. We designed and constructed a broadband diffuse optical spectroscopy (DOS) prototype system to measure bulk tissue absorption and scattering spectra between 650 and 1000 nm capable of accurately determining these tissue hemoglobin component concentrations in vivo. Our purpose was to assess the feasibility of using DOS to optically monitor tissue [OHb], [RHb], StO2, and total tissue hemoglobin concentration ([THb]=[OHb]+[RHb]) during HBOC infusion using a rabbit hypovolemic shock model. The DOS prototype probe was placed on the shaved inner thigh muscle of the hind leg to assess concentrations of [OHb], [RHb], [THb], as well as StO2. Hemorrhagic shock was induced in intubated New Zealand white rabbits (N=6) by withdrawing blood via a femoral arterial line to 20% blood loss (10-15 cc/kg). Hemoglobin glutamer-200 (Hb-200) 1:1 volume resuscitation was administered following the hemorrhage. These values were compared against traditional invasive measurements, serum hemoglobin concentration (sHGB), systemic blood pressure, heart rate, and blood gases. DOS revealed increases of [THb], [OHb], and tissue hemoglobin oxygen saturation after Hb-200 infusion, while blood total hemoglobin values continued did not increase; we speculate, due to hyperosmolality induced hemodilution. DOS enables noninvasive in vivo monitoring of tissue hemoglobin and oxygenation parameters during shock and volume expansion with HBOC and potentially enables the assessment of efficacy of resuscitation efforts using artificial blood substitutes.

  3. Effects of simultaneous radiofrequency radiation and chemical exposure of mammalian cells. Volume 1. Annual report, 2 January-31 December 1984

    SciTech Connect

    Meltz, M.L.

    1987-08-01

    The major objective of this project was to determine whether radiofrequency radiation (RFR), at power densities and specific absorption rate (SAR) values which can result in temperature increases in the exposure medium, can affect the extent of chemically induced toxicity, mutagenicity, sister chromatid exchange, or chromosome aberrations in mammalian cells. The in-vitro system used for toxicity and mutagenicity studies is the mouse leukemic L5178Y cell thymidine kinase locus mutation assay.

  4. Recent advances in mammalian protein production

    PubMed Central

    Bandaranayake, Ashok D.; Almo, Steven C.

    2014-01-01

    Mammalian protein production platforms have had a profound impact in many areas of basic and applied research, and an increasing number of blockbuster drugs are recombinant mammalian proteins. With global sales of these drugs exceeding US$120 billion per year, both industry and academic research groups continue to develop cost effective methods for producing mammalian proteins to support preclinical and clinical evaluations of potential therapeutics. While a wide range of platforms have been successfully exploited for laboratory use, the bulk of recent biologics have been produced in mammalian cell lines due to the requirement for post translational modification and the biosynthetic complexity of the target proteins. In this review we highlight the range of mammalian expression platforms available for recombinant protein production, as well as advances in technologies for the rapid and efficient selection of highly productive clones. PMID:24316512

  5. Methyglyoxal administration induces modification of hemoglobin in experimental rats: An in vivo study.

    PubMed

    Banerjee, Sauradipta

    2017-02-01

    Methylglyoxal, a highly reactive α-oxoaldehyde, increases in diabetic condition and reacts with proteins to form advanced glycation end products (AGEs) following Maillard-like reaction. In the present study, the effect of methylglyoxal on experimental rat hemoglobin in vivo has been investigated with respect to structural alterations and amino acid modifications, after external administration of the α-dicarbonyl compound in animals. Different techniques, mostly biophysical, were used to characterize and compare methylglyoxal-treated rat hemoglobin with that of control, untreated rat hemoglobin. In comparison with methylglyoxal-untreated, control rat hemoglobin, hemoglobin of methylglyoxal-treated rats (32mg/kgbodywt.dose) exhibited slightly decreased absorbance around 280nm, reduced intrinsic fluorescence and lower surface hydrophobicity. The secondary structures of hemoglobin of control and methylglyoxal-treated rats were more or less identical with the latter exhibiting slightly increased α-helicity compared to the former. Compared to control rat hemoglobin, methylglyoxal-treated rat hemoglobin showed higher stability. Peptide mass fingerprinting analysis revealed modifications of Arg-31α, Arg-92α and Arg-104β of methylglyoxal-treated rat hemoglobin to hydroimidazolone adducts. The modifications thus appear to be associated with the observed structural alterations of the heme protein. Considering the increased level of methylglyoxal in diabetes mellitus as well as its high reactivity, AGE-induced modifications may have physiological significance.

  6. Degradation of bioabsorbable Mg-based alloys: Assessment of the effects of insoluble corrosion products and joint effects of alloying components on mammalian cells.

    PubMed

    Grillo, Claudia A; Alvarez, Florencia; Fernández Lorenzo de Mele, Mónica A

    2016-01-01

    This work is focused on the processes occurring at the bioabsorbable metallic biomaterial/cell interfaces that may lead to toxicity. A critical analysis of the results obtained when degradable metal disks (pure Mg and rare earth-containing alloys (ZEK100 alloys)) are in direct contact with cell culture and those obtained with indirect methods such as the use of metal salts and extracts was made. Viability was assessed by Acridine Orange dye, neutral red and clonogenic assays. The effects of concentration of corrosion products and possible joint effects of the binary and ternary combinations of La, Zn and Mg ions, as constituents of ZEK alloys, were evaluated on a mammalian cell culture. In all cases more detrimental effects were found for pure Mg than for the alloys. Experiments with disks showed that gradual alterations in pH and in the amount of corrosion products were better tolerated by cells and resulted in higher viability than abrupt changes. In addition, viability was dependent on the distance from the source of ions. Experiments with extracts showed that the effect of insoluble degradation products was highly detrimental. Indirect tests with Zn ions revealed that harmful effects may be found at concentrations ≥ 150 μM and at ≥ 100 μM in mixtures with Mg. These mixtures lead to more deleterious effects than single ions. Results highlight the need to develop a battery of tests to evaluate the biocompatibility of bioabsorbable biomaterials.

  7. Hemoglobin

    MedlinePlus

    ... Failure of the right side of the heart ( cor pulmonale ) Severe chronic obstructive pulmonary disease (COPD) Scarring or ... chronic disease Aplastic anemia Bleeding CBC blood test Cor pulmonale Diabetes Drug-induced immune hemolytic anemia Erythropoietin test ...

  8. Determination Of Ph Including Hemoglobin Correction

    DOEpatents

    Maynard, John D.; Hendee, Shonn P.; Rohrscheib, Mark R.; Nunez, David; Alam, M. Kathleen; Franke, James E.; Kemeny, Gabor J.

    2005-09-13

    Methods and apparatuses of determining the pH of a sample. A method can comprise determining an infrared spectrum of the sample, and determining the hemoglobin concentration of the sample. The hemoglobin concentration and the infrared spectrum can then be used to determine the pH of the sample. In some embodiments, the hemoglobin concentration can be used to select an model relating infrared spectra to pH that is applicable at the determined hemoglobin concentration. In other embodiments, a model relating hemoglobin concentration and infrared spectra to pH can be used. An apparatus according to the present invention can comprise an illumination system, adapted to supply radiation to a sample; a collection system, adapted to collect radiation expressed from the sample responsive to the incident radiation; and an analysis system, adapted to relate information about the incident radiation, the expressed radiation, and the hemoglobin concentration of the sample to pH.

  9. Hemoglobin Labeled by Radioactive Lysine

    DOE R&D Accomplishments Database

    Bale, W. F.; Yuile, C. L.; DeLaVergne, L.; Miller, L. L.; Whipple, G. H.

    1949-12-08

    This paper reports on the utilization of tagged epsilon carbon of DL-lysine by a dog both anemic and hypoproteinemic due to repeated bleeding plus a diet low in protein. The experiment extended over period of 234 days, a time sufficient to indicate an erythrocyte life span of at least 115 days based upon the rate of replacement of labeled red cell proteins. The proteins of broken down red cells seem not to be used with any great preference for the synthesis of new hemoglobin.

  10. Effect of the method to measure levels of glycated hemoglobin on individual clinical decisions: comparison of an immunoassay with high-performance liquid chromatography.

    PubMed

    García-Alcalá, Héctor; Ruiz-Argüelles, Alejandro; Cedillo-Carvallo, Beatriz

    2009-09-01

    Our objective was to compare in a prospective study the clinical performance of the reference and an alternative method to measure blood levels of glycated hemoglobin. A total of 178 samples from patients with diabetes were tested by both methods, and results were analyzed for correlation and comparison of sensitivity, specificity, and positive and negative predictive values to classify patients according to glycemic control. There was a significant linear correlation between methods (r = 0.645; P < .0001); the sensitivity, specificity, and positive and negative predictive values of the alternative method to identify patients with controlled and uncontrolled status were as follows: controlled, 88%, 78%, 77%, and 88%; and uncontrolled, 78%, 88%, 88%, and 77%, respectively. Results show that although the results of both methods show a statistically significant correlation, the ability of the alternative method to correctly classify individual patients according to glycemic control status is far from optimal.

  11. Area and mammalian elevational diversity.

    PubMed

    McCain, Christy M

    2007-01-01

    Elevational gradients hold enormous potential for understanding general properties of biodiversity. Like latitudinal gradients, the hypotheses for diversity patterns can be grouped into historical explanations, climatic drivers, and spatial hypotheses. The spatial hypotheses include the species-area effect and spatial constraint (mid-domain effect null models). I test these two spatial hypotheses using regional diversity patterns for mammals (non-volant small mammals and bats) along 34 elevational gradients spanning 24.4 degrees S-40.4 degrees N latitude. There was high variability in the fit to the species-area hypothesis and the mid-domain effect. Both hypotheses can be eliminated as primary drivers of elevational diversity. Area and spatial constraint both represent sources of error rather than mechanisms underlying these mammalian diversity patterns. Similar results are expected for other vertebrate taxa, plants, and invertebrates since they show comparable distributions of elevational diversity patterns to mammalian patterns.

  12. Effect of atrazine and fenitrothion at no-observed-effect-levels (NOEL) on amphibian and mammalian corticosterone-binding-globulin (CBG).

    PubMed

    Hernández, Sandra E; Sernia, Conrad; Bradley, Adrian J

    2014-11-04

    This study determines the effect of atrazine and fenitrothion no-observed-effect-levels (NOEL) on the binding of corticosterone (B) to corticosterone-binding-globulin (CBG) in an amphibian and a mammal. Plasma from five cane toads and five Wistar rats was exposed to atrazine and fenitrothion at the NOEL approved for Australian fresh water residues and by the World Health Organization (WHO). The concentration required to displace 50% (IC50) of B binding to CBG was determined by a competitive microdialysis protein assay. Competition studies showed that both atrazine and fenitrothion at NOEL are able to compete with B for CBG binding sites in toad and rat plasma. The IC50 levels for atrazine in toads and rats were 0.004 nmol/l and 0.09 nmol/l respectively. In the case of fenitrothion the IC50 level found in toads was 0.007 nmol/l, and 0.025 nmol/l in rats. Plasma dilution curves showed parallelism with the curve of B, demonstrating that these agro-chemicals are competitively inhibiting binding to CBG. The displacement of B by atrazine and fenitrothion would affect the total:free ratio of B and consequently disrupt the normal stress response. This is the first time that the potential disruptive effect of atrazine and fenitrothion on B-CBG interaction at the NOELs has been demonstrated in amphibian and mammalian models.

  13. Radiation-induced changes in the optical properties of hemoglobin molecule.

    PubMed

    Selim, Nabila S; El-Marakby, Seham M

    2010-06-01

    Adult male Albino rats were exposed to different doses of gamma radiation from Cs-137 source. Hemoglobin samples were analyzed 24 h after irradiation. The UV-visible spectrum of hemoglobin molecule was measured in the range 200-700 nm. The overall spectrum of the hemoglobin molecule showed hypochromicity that increased with dose increase. To investigate the effect of radiation on the hemoglobin molecule, different parameters of the spectrum were calculated: molar absorption coefficient, absorption cross-section, transition dipole moment, dipole length, the optical energy gap and activation energy for each characteristic peak. The obtained results revealed that the radiation effect can induce rearrangement of the transition dipole moments and change molecular energy levels of the hemoglobin molecule.

  14. Radiation-induced changes in the optical properties of hemoglobin molecule

    NASA Astrophysics Data System (ADS)

    Selim, Nabila S.; El-Marakby, Seham M.

    2010-06-01

    Adult male Albino rats were exposed to different doses of gamma radiation from Cs-137 source. Hemoglobin samples were analyzed 24 h after irradiation. The UV-visible spectrum of hemoglobin molecule was measured in the range 200-700 nm. The overall spectrum of the hemoglobin molecule showed hypochromicity that increased with dose increase. To investigate the effect of radiation on the hemoglobin molecule, different parameters of the spectrum were calculated: molar absorption coefficient, absorption cross-section, transition dipole moment, dipole length, the optical energy gap and activation energy for each characteristic peak. The obtained results revealed that the radiation effect can induce rearrangement of the transition dipole moments and change molecular energy levels of the hemoglobin molecule.

  15. Effects of Pleistocene environmental changes on the distribution and community structure of the mammalian fauna of Mexico

    NASA Astrophysics Data System (ADS)

    Ceballos, Gerardo; Arroyo-Cabrales, Joaquín; Ponce, Eduardo

    2010-05-01

    Biological communities in Mexico experienced profound changes in species composition and structure as a consequence of the environmental fluctuations during the Pleistocene. Based on the recent and fossil Mexican mammal checklists, we determine the distribution, composition, diversity, and community structure of late Pleistocene mammalian faunas, and analyze extinction patterns and response of individual species to environmental changes. We conclude that (1) differential extinctions occurred at family, genus, and species level, with a major impact on species heavier than 100 kg, including the extinction all proboscideans and several ruminants; (2) Pleistocene mammal communities in Mexico were more diverse than recent ones; and (3) the current assemblages of species are relatively young. Furthermore, Pleistocene relicts support the presence of biogeographic corridors; important refugia existed as well as centers of speciation in isolated regions. We identified seven corridors: eastern USA-Sierra Madre Oriental corridor, Rocky Mountains-Sierra Madre Occidental corridor, Central United States-Northern Mexico corridor, Transvolcanic Belt-Sierra Madre del Sur corridor, western USA-Baja California corridor, Tamaulipas-Central America gulf lowlands corridor, and Sonora-Central America Pacific lowlands corridor. Our study suggests that present mammalian assemblages are very different than the ones in the late Pleistocene.

  16. Nitric oxide from nitrite reduction by hemoglobin in the plasma and erythrocytes

    PubMed Central

    Chen, Kejing; Piknova, Barbora; Pittman, Roland N.; Schechter, Alan N.; Popel, Aleksander S.

    2008-01-01

    Experimental evidence has shown that nitrite anion plays a key role in one of the proposed mechanisms for hypoxic vasodilation, in which the erythrocyte acts as a NO generator and deoxygenated hemoglobin in pre-capillary arterioles reduces nitrite to NO, which contributes to vascular smooth muscle relaxation. However, because of the complex reactions among nitrite, hemoglobin, and the NO that is formed, the amount of NO delivered by this mechanism under various conditions has not been quantified experimentally. Furthermore, paracrine NO is scavenged by cell-free hemoglobin, as shown by studies of diseases characterized by extensive hemolysis (e.g., sickle cell disease) and the administration of hemoglobin-based oxygen carriers. Taking into consideration the free access of cell-free hemoglobin to the vascular wall and its ability to act as a nitrite reductase, we have now examined the hypothesis that in hypoxia this cell-free hemoglobin could serve as an additional endocrine source of NO. In this study, we constructed a multicellular model to characterize the amount of NO delivered by the reaction of nitrite with both intraerythrocytic and cell-free hemoglobin, while intentionally neglecting all other possible sources of NO in the vasculature. We also examined the roles of hemoglobin molecules in each compartment as nitrite reductases and NO scavengers using the model. Our calculations show that: (1) ~0.04 pM NO from erythrocytes could reach the smooth muscle if free diffusion were the sole export mechanism; however, this value could rise to ~43 pM with a membrane-associated mechanism that facilitated NO release from erythrocytes; the results also strongly depend on the erythrocyte membrane permeability to NO; (2) despite the closer proximity of cell-free hemoglobin to the smooth muscle, cell-free hemoglobin reaction with nitrite generates approximately 0.02 pM of free NO that can reach the vascular wall, because of a strong self-capture effect. However, it is worth

  17. Nanoscale spectroscopy and imaging of hemoglobin.

    PubMed

    Kennedy, Eamonn; Yarrow, Fiona; Rice, James H

    2011-09-01

    Sub diffraction limited infrared absorption imaging of hemoglobin was performed by coupling IR optics with an atomic force microscope. Comparisons between the AFM topography and IR absorption images of micron sized hemoglobin features are presented, along with nanoscale IR spectroscopic analysis of the metalloprotein.

  18. Spectrophotometric Properties of Hemoglobin: Classroom Applications.

    ERIC Educational Resources Information Center

    Frary, Roger

    1997-01-01

    Discusses simple and safe techniques that can be used in the educational laboratory to study hemoglobin. Discusses the spectral properties of hemoglobin, spectral-absorbence curves of oxyhemoglobin and carboxyhemoglobin, tracking the conversion of oxyhemoglobin to methemoglobin, and changing from the oxyhemoglobin to deoxyhemoglobin conformation.…

  19. Determination of Human Hemoglobin Derivatives.

    PubMed

    Attia, Atef M M; Ibrahim, Fatma A A; Abd El-Latif, Noha A; Aziz, Samir W; Abdelmottaleb Moussa, Sherif A; Elalfy, Mohsen S

    2015-01-01

    The levels of the inactive hemoglobin (Hb) pigments [such as methemoglobin (metHb), carboxyhemoglobin (HbCO) and sulfohemoglobin (SHb)] and the active Hb [in the oxyhemoglobin (oxyHb) form] as well as the blood Hb concentration in healthy non pregnant female volunteers were determined using a newly developed multi-component spectrophotometric method. The results of this method revealed values of SHb% in the range (0.0727-0.370%), metHb% (0.43-1.0%), HbCO% (0.4-1.52%) and oxyHb% (97.06-98.62%). Furthermore, the results of this method revealed values of blood Hb concentration in the range (12.608-15.777 g/dL). The method is highly sensitive, accurate and reproducible.

  20. Anti-Tumor Effects of Novel 5-O-Acyl Plumbagins Based on the Inhibition of Mammalian DNA Replicative Polymerase Activity

    PubMed Central

    Kawamura, Moe; Kuriyama, Isoko; Maruo, Sayako; Kuramochi, Kouji; Tsubaki, Kazunori; Yoshida, Hiromi; Mizushina, Yoshiyuki

    2014-01-01

    We previously found that vitamin K3 (menadione, 2-methyl-1,4-naphthoquinone) inhibits the activity of human mitochondrial DNA polymerase γ (pol γ). In this study, we focused on plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone), and chemically synthesized novel plumbagins conjugated with C2:0 to C22:6 fatty acids (5-O-acyl plumbagins). These chemically modified plumbagins enhanced mammalian pol inhibition and their cytotoxic activity. Plumbagin conjugated with chains consisting of more than C18-unsaturated fatty acids strongly inhibited the activities of calf pol α and human pol γ. Plumbagin conjugated with oleic acid (C18:1-acyl plumbagin) showed the strongest suppression of human colon carcinoma (HCT116) cell proliferation among the ten synthesized 5-O-acyl plumbagins. The inhibitory activity on pol α, a DNA replicative pol, by these compounds showed high correlation with their cancer cell proliferation suppressive activity. C18:1-Acyl plumbagin selectively inhibited the activities of mammalian pol species, but did not influence the activities of other pols and DNA metabolic enzymes tested. This compound inhibited the proliferation of various human cancer cell lines, and was the cytotoxic inhibitor showing strongest inhibition towards HT-29 colon cancer cells (LD50 = 2.9 µM) among the nine cell lines tested. In an in vivo anti-tumor assay conducted on nude mice bearing solid tumors of HT-29 cells, C18:1-acyl plumbagin was shown to be a promising tumor suppressor. These data indicate that novel 5-O-acyl plumbagins act as anti-cancer agents based on mammalian DNA replicative pol α inhibition. Moreover, the results suggest that acylation of plumbagin is an effective chemical modification to improve the anti-cancer activity of vitamin K3 derivatives, such as plumbagin. PMID:24520419

  1. MP4, a new nonvasoactive polyethylene glycol-hemoglobin conjugate.

    PubMed

    Winslow, Robert M

    2004-09-01

    A new hemoglobin derivative, MP4, for use as a temporary oxygen-carrying plasma expander, has been prepared. The design of the molecule is based on novel criteria for optimized efficacy and safety, which include increased molecular radius, increased viscosity, increased oncotic pressure, and reduced p50. The chemical entity, MalPEG-Hb, is formulated at 4.2 g/dL in lactated Ringer's solution (MP4). It has a p50 of 5-6 mm Hg, oncotic pressure of 49 mm Hg and viscosity of 2.2 cPs. After 50% exchange transfusion with MP4, rats survive a 60% controlled hemorrhage in spite of total hemoglobin of 7.8 g/dL and plasma hemoglobin concentration of 1.6 g/dL. Although its binding affinity for NO is not different from that of purified hemoglobin A, it does not produce hypertension in a number of animal models and does not cause vasoconstriction in hamster microcirculation. Oxygen supply to tissue has been confirmed by direct observation in the hamster skinfold model, in which O2 release in precapillary and capillary vessels was quantified. The data demonstrate that the effectiveness of MP4 results from its ability to conserve O2 in precapillary vessels and release O2 in capillaries, thereby "targeting" O2 to hypoxic tissue. Preservation of functional capillary density and prevention of vasoconstriction further contribute to the effectiveness of this new formulation. MP4 is currently being tested in humans.

  2. Monoclonal antibodies specific for sickle cell hemoglobin

    SciTech Connect

    Jensen, R.H.; Vanderlaan, M.; Grabske, R.J.; Branscomb, E.W.; Bigbee, W.L.; Stanker, L.H.

    1985-01-01

    Two mouse hybridoma cell lines were isolated which produce monoclonal antibodies that bind hemoglobin S. The mice were immunized with peptide-protein conjugates to stimulate a response to the amino terminal peptide of the beta chain of hemoglobin S, where the single amino acid difference between A and S occurs. Immunocharacterization of the antibodies shows that they bind specifically to the immunogen peptide and to hemoglobin S. The specificity for S is high enough that one AS cell in a mixture with a million AA cells is labeled by antibody, and such cells can be analyzed by flow cytometry. Immunoblotting of electrophoretic gels allows definitive identification of hemoglobin S as compared with other hemoglobins with similar electrophoretic mobility. 12 references, 4 figures.

  3. Degradation of human hemoglobin by Prevotella intermedia.

    PubMed

    Guan, Su-Min; Nagata, Hideki; Shizukuishi, Satoshi; Wu, Jun-Zheng

    2006-01-01

    In this study, the ability of Prevotella intermedia, an obligate anaerobic rod, to degrade human hemoglobin was determined by SDS-PAGE and the degradation was quantified by scanning densitometry. Both bacterial cells and culture supernatants degraded hemoglobin. The hemoglobin degradation by P. intermedia was time-dependent, heat sensitive, pH related and was not influenced by iron restriction. Inhibition studies demonstrated that a cysteine protease might be involved in hemoglobin degradation and this protease might require metal ions for its activity and it might be thiol-requiring and trypsin-inducible. The results indicate that P. intermedia is capable to release heme from hemoglobin, hence provide a source of iron for its proliferation.

  4. Structure and reactivity of hexacoordinate hemoglobins

    PubMed Central

    Kakar, Smita; Hoffman, Federico G.; Storz, Jay F.; Fabian, Marian; Hargrove, Mark S.

    2015-01-01

    The heme prosthetic group in hemoglobins is most often attached to the globin through coordination of either one or two histidine side chains. Those proteins with one histidine coordinating the heme iron are called “pentacoordinate” hemoglobins, a group represented by red blood cell hemoglobin and most other oxygen transporters. Those with two histidines are called “hexacoordinate hemoglobins”, which have broad representation among eukaryotes. Coordination of the second histidine in hexacoordinate Hbs is reversible, allowing for binding of exogenous ligands like oxygen, carbon monoxide, and nitric oxide. Research over the past several years has produced a fairly detailed picture of the structure and biochemistry of hexacoordinate hemoglobins from several species including neuroglobin and cytoglobin in animals, and the nonsymbiotic hemoglobins in plants. However, a clear understanding of the physiological functions of these proteins remains an elusive goal. PMID:20933319

  5. Inhibition of pseudoperoxiadse activity of human red blood cell hemoglobin by methocarbamol.

    PubMed

    Minai-Tehrani, Dariush; Toofani, Sara; Yazdi, Fatemeh; Minai-Tehrani, Arash; Mollasalehi, Hamidreza; Bakhtiari Ziabari, Kourosh

    2017-01-01

    After red blood cells lysis, hemoglobin is released to blood circulation. Hemoglobin is carried in blood by binding to haptoglobin. In normal individuals, no free hemoglobin is observed in the blood, because most of the hemoglobin is in the form of haptoglobin complex. In some diseases that are accompanied by hemolysis, the amount of released hemoglobin is higher than its complementary haptoglobin. As a result, free hemoglobin appears in the blood, which is a toxic compound for these patients and may cause renal failure, hypertensive response and risk of atherogenesis. Free hemoglobin has been determined to have peroxidase activity and considered a pseudoenzyme. In this study, the effect of methocarbamol on the peroxidase activity of human hemoglobin was investigated. Our results showed that the drug inhibited the pseudoenzyme by un-competitive inhibition. Both Km and Vmax decreased by increasing the drug concentration. Ki and IC50 values were determined as 6 and 10mM, respectively. Docking results demonstrated that methocarbamol did not attach to heme group directly. A hydrogen bond linked NH2 of carbamate group of methocarbamol to the carboxyl group of Asp126 side chain. Two other hydrogen bonds could be also observed between hydroxyl group of the drug and Ser102 and Ser133 residues of the pseudoenzyme.

  6. Investigations on the binding of human hemoglobin with orange I and orange II.

    PubMed

    Wang, Yan-Qing; Zhang, Hong-Mei

    2012-08-01

    The interactions between human hemoglobin and orange I (or orange II) were investigated by UV/vis absorption, circular dichroism, fluorescence spectra techniques, and molecular modeling method. Orange I and orange II effectively quenched the intrinsic fluorescence of human hemoglobin by static quenching. The processes of the binding orange I and orange II on human hemoglobin were spontaneous molecular interaction procedure with hydrogen bonds, van der Waals force, hydrophobic and electrostatic interactions according to van't Hoff equation and molecular modeling. There is a single class of binding site of orange I (orange II) in human hemoglobin and the molecular modeling study shows that orange I and orange II are dipped into α(2) chain. The results of CD, synchronous fluorescence and three-dimensional fluorescence spectra indicated a small loss of α-helical secondary structure of human hemoglobin induced by orange I and orange II.

  7. The effects of preserved red blood cells on the severe adverse events observed in patients infused with hemoglobin based oxygen carriers.

    PubMed

    Valeri, C Robert; Ragno, Gina

    2008-01-01

    The severe adverse events observed in patients who received hemoglobin based oxygen carriers (HBOCs) were associated with the Ringer's D.L lactate resuscitative solution administered and to the excipient used in the HBOCs containing Ringer's D,L lactate and the length of storage of the preserved RBC administered to the patient at the time that the HBOCs were infused. This paper reports the quality of the red blood cells preserved in the liquid state at 4 degrees C and that of previously frozen RBCs stored at 4 degrees C with regard to their survival, function and safety. Severe adverse events have been observed related to the length of storage of the liquid preserved RBC stored at 4 degrees C prior to transfusion. The current methods to preserve RBC in the liquid state in additive solutions at 4 degrees C maintain their survival and function for only 2 weeks. The freezing of red blood cells with 40% W/V glycerol and storage at -80 degrees C allows for storage at -80 degrees C for 10 years and following thawing, deglycerolization and storage at 4 degrees C in the additive solution (AS-3, Nutricel) for 2 weeks with acceptable 24 hour posttransfusion survival, less than 1% hemolysis, and moderately impaired oxygen transport function with no associated adverse events. Frozen deglycerolized RBCs are leukoreduced and contain less than 5% of residual plasma and non-plasma substances. Frozen deglycerolized RBCs are the ideal RBC product to transfuse patients receiving HBOCs.

  8. Effects of N-acetyl-L-cysteine-capped CdTe quantum dots on bovine serum albumin and bovine hemoglobin: isothermal titration calorimetry and spectroscopic investigations.

    PubMed

    Sun, Haoyu; Cui, Erqian; Tan, Zhigang; Liu, Rutao

    2014-12-01

    The interactions of N-acetyl-L-cysteine-capped CdTe quantum dots (QDs) with bovine serum albumin (BSA) and bovine hemoglobin (BHb) were investigated by isothermal titration calorimetry (ITC), fluorescence, synchronous fluorescence, fluorescence lifetime, ultraviolet-visible absorption, and circular dichroism techniques. Fluorescence data of BSA-QDs and BHb-QDs revealed that the quenching was static in every system. While CdTe QDs changed the microenvironment of tryptophan in BHb, the microenvironment of BSA kept unchanged. Adding CdTe QDs affected the skeleton and secondary structure of the protein (BSA and BHb). The ITC results indicated that the interaction between the protein (BSA and BHb) and QDs-612 was spontaneous and the predominant force was hydrophobic interaction. In addition, the binding constants were determined to be 1.19 × 10(5) L mol(-1) (BSA-QDs) and 2.19 × 10(5) L mol(-1) (BHb-QDs) at 298 K. From these results, we conclude that CdTe QDs have a larger impact on the structure of BHb than BSA.

  9. Circadian Plasticity of Mammalian Inhibitory Interneurons

    PubMed Central

    2017-01-01

    Inhibitory interneurons participate in all neuronal circuits in the mammalian brain, including the circadian clock system, and are indispensable for their effective function. Although the clock neurons have different molecular and electrical properties, their main function is the generation of circadian oscillations. Here we review the circadian plasticity of GABAergic interneurons in several areas of the mammalian brain, suprachiasmatic nucleus, neocortex, hippocampus, olfactory bulb, cerebellum, striatum, and in the retina. PMID:28367335

  10. Targeted O2 delivery by low-p50 hemoglobin: a new basis for hemoglobin-based oxygen carriers.

    PubMed

    Winslow, Robert M

    2005-01-01

    We have proposed new criteria for a successful cell-free, hemoglobin-based O2 carrier. These include increased molecular radius, increased viscosity, increased oncotic pressure, and reduced p50. A new molecule, MalPEG-Hb, formulated at 4.2g/dL in lactated Ringer's solution (MP4), has been produced according to these new criteria. MP4 has a p50 of 5-6 mm Hg, oncotic pressure of 49mm Hg and viscosity of 2.2cPs. After 50% exchange transfusion with MP4, rats survive a 60% controlled hemorrhage in spite of total hemoglobin of 7.8 g/dL and plasma hemoglobin concentration of 1.6 g/dL. This model results in 50% mortality in control animals and 100% mortality in animals exchange-transfused with either crosslinked or polymerized hemoglobin. Oxygen supply to tissue was measured directly in the hamster skinfold model, in which O2 release in precapillary and capillary vessels can be quantified. The data demonstrate that the effectiveness of MP4 results from its ability to conserve O2 in precapillary vessels and release O2 in capillaries, thereby "targeting" O2 to hypoxic tissue. Preservation of functional capillary density and prevention of vasoconstriction further contribute to the effectiveness of this new formulation.

  11. Mutational analysis of hemoglobin binding and heme utilization by a bacterial hemoglobin receptor.

    PubMed

    Fusco, W G; Choudhary, N R; Council, S E; Collins, E J; Leduc, I

    2013-07-01

    Iron is an essential nutrient for most living organisms. To acquire iron from their environment, Gram-negative bacteria use TonB-dependent transporters that bind host proteins at the bacterial surface and transport iron or heme to the periplasm via the Ton machinery. TonB-dependent transporters are barrel-shaped outer membrane proteins with 22 transmembrane domains, 11 surface-exposed loops, and a plug domain that occludes the pore. To identify key residues of TonB-dependent transporters involved in hemoglobin binding and heme transport and thereby locate putative protective epitopes, the hemoglobin receptor of Haemophilus ducreyi HgbA was used as a model of iron/heme acquisition from hemoglobin. Although all extracellular loops of HgbA are required by H. ducreyi to use hemoglobin as a source of iron/heme, we previously demonstrated that hemoglobin binding by HgbA only involves loops 5 and 7. Using deletion, substitution, and site-directed mutagenesis, we were able to differentiate hemoglobin binding and heme acquisition by HgbA. Deletion or substitution of the GYEAYNRQWWA region of loop 5 and alanine replacement of selected histidines affected hemoglobin binding by HgbA. Conversely, mutation of the phenylalanine in the loop 7 FRAP domain or substitution of the NRQWWA motif of loop 5 significantly abrogated utilization of heme from hemoglobin. Our findings show that hemoglobin binding and heme utilization by a bacterial hemoglobin receptor involve specific motifs of HgbA.

  12. Preparation of Hemoglobin-Containing Microcapsules.

    DTIC Science & Technology

    1982-04-01

    L -i2 801 PREPARRTION OF HEMOGLOBIN-CONTAINING MICROCAPSULES (U) i/i I SRI INTERNATIONAL MENLO PRK CA Z REYES APR 82 UNLSSFE SRI1-2254-2 DRMDi,7-8@-C...R oI• _ AD I PREPARATION OF HEMOGLOBIN- /2 o ) CONTAINING MICROCAPSULES . 00 ANNUAL AND FINAL REPORT ZOILA REYES, Ph.D. APRIL 1982 Supported by U.S...1/31/82) PREPARATION OF HEMOGLOBIN-CONTAINING MICROCAPSULES 6. PERFORMING ORG. REPOR’ NUMBER 2254-2 7. AUTHOR(s) 8. CONTRACT OR GRANT NUMBER(s) Zoila

  13. Interaction of Human Hemoglobin with Methotrexate

    NASA Astrophysics Data System (ADS)

    Zaharia, M.; Gradinaru, R.

    2015-05-01

    This study focuses on the interaction between methotrexate and human hemoglobin using steady-state ultraviolet-visible and fluorescence quenching methods. Fluorescence quenching was found to be valuable in assessing drug binding to hemoglobin. The quenching of methotrexate is slightly smaller than the quenching observed with related analogs (dihydrofolate and tetrahydrofolate). The quenching studies were performed at four different temperatures and various pH values. The number of binding sites for tryptophan is ~1. Parameter-dependent assays revealed that electrostatic forces play an essential role in the methotrexate-hemoglobin interaction. Furthermore, the complex was easily eluted using gel filtration chromatography.

  14. Differential effects of the recombinant toxin PnTx4(5-5) from the spider Phoneutria nigriventer on mammalian and insect sodium channels.

    PubMed

    Paiva, Ana L B; Matavel, Alessandra; Peigneur, Steve; Cordeiro, Marta N; Tytgat, Jan; Diniz, Marcelo R V; de Lima, Maria Elena

    2016-02-01

    The toxin PnTx4(5-5) from the spider Phoneutria nigriventer is extremely toxic/lethal to insects but has no macroscopic behavioral effects observed in mice after intracerebral injection. Nevertheless, it was demonstrated that it inhibits the N-methyl-d-aspartate (NMDA) - subtype of glutamate receptors of cultured rat hippocampal neurons. PnTx4(5-5) has 63% identity to PnTx4(6-1), another insecticidal toxin from P. nigriventer, which can slow down the sodium current inactivation in insect central nervous system, but has no effect on Nav1.2 and Nav1.4 rat sodium channels. Here, we have cloned and heterologous expressed the toxin PnTx4(5-5) in Escherichia coli. The recombinant toxin rPnTx4(5-5) was tested on the sodium channel NavBg from the cockroach Blatella germanica and on mammalian sodium channels Nav1.2-1.6, all expressed in Xenopus leavis oocytes. We showed that the toxin has different affinity and mode of action on insect and mammalian sodium channels. The most remarkable effect was on NavBg, where rPnTx4(5-5) strongly slowed down channel inactivation (EC50 = 212.5 nM), and at 1 μM caused an increase on current peak amplitude of 105.2 ± 3.1%. Interestingly, the toxin also inhibited sodium current on all the mammalian channels tested, with the higher current inhibition on Nav1.3 (38.43 ± 8.04%, IC50 = 1.5 μM). Analysis of activation curves on Nav1.3 and Nav1.5 showed that the toxin shifts channel activation to more depolarized potentials, which can explain the sodium current inhibition. Furthermore, the toxin also slightly slowed down sodium inactivation on Nav1.3 and Nav1.6 channels. As far as we know, this is the first araneomorph toxin described which can shift the sodium channel activation to more depolarized potentials and also slows down channel inactivation.

  15. Effects of H2O2 on insulin signaling the glucose transport system in mammalian skeletal muscle.

    PubMed

    Henriksen, Erik J

    2013-01-01

    Hydrogen peroxide (H2O2) is an important regulator of cellular events leading to glucose transport activation in mammalian skeletal muscle. In the absence of insulin, H2O2 in the low micromolar range engages the canonical IRS-1/PI3K/Akt-dependent insulin signaling pathway, as well as other signaling elements (AMPK and p38 MAPK), to increase basal glucose transport activity. In contrast, in the presence of insulin, H2O2 antagonizes insulin signaling by recruitment of various deleterious serine/threonine kinases, producing a state of insulin resistance. Here, we describe the H2O2 enzymatic-generating system, utilizing glucose oxidase, that has been used to investigate the impact of H2O2 on cellular signaling mechanisms related to glucose transport activity in isolated rat skeletal muscle preparations, such as the soleus. By varying the glucose oxidase concentration in the medium, target ranges of steady-state H2O2 concentrations (30-90 μM) can be attained for up to 6h, with subsequent assessment of cellular signaling and glucose transport activity.

  16. The Effect of Non-surgical Periodontal Therapy on Hemoglobin A1c Levels in Persons with Type 2 Diabetes and Chronic Periodontitis: A Randomized Clinical Trial

    PubMed Central

    Engebretson, Steven P.; Hyman, Leslie G.; Michalowicz, Bryan S.; Schoenfeld, Elinor R.; Gelato, Marie C.; Hou, Wei; Seaquist, Elizabeth R.; Reddy, Michael S.; Lewis, Cora E.; Oates, Thomas W.; Tripathy, Devjit; Katancik, James A.; Orlander, Philip R.; Paquette, David W.; Hanson, Naomi Q.; Tsai, Michael Y.

    2014-01-01

    Importance Chronic periodontitis, a destructive inflammatory disorder of the supporting structures of the teeth, is prevalent in patients with diabetes. Limited evidence suggests that periodontal therapy may improve glycemic control. Objective To determine if non-surgical periodontal treatment reduces hemoglobin A1c (HbA1c) in persons with type 2 diabetes (DM) and moderate to advanced chronic periodontitis. Design, Setting and Participants The Diabetes and Periodontal Therapy Trial (DPTT) is a 6-month, single-masked, randomized, multi-center clinical trial. Participants had DM, were taking stable doses of medications, had HbA1c ≥7% and <9%, and untreated periodontitis. Five hundred fourteen participants were enrolled between November 2009 and March 2012 from diabetes and dental clinics and communities affiliated with five academic medical centers. Intervention The treatment group (n=257) received scaling and root planing plus chlorhexidine oral rinse at baseline, and supportive periodontal therapy at three and six months. The control group (n=257) received no treatment for six months. Main Outcome Measure Difference in HbA1c change from baseline between groups at six months. Secondary outcomes included changes in probing pocket depths, clinical attachment loss, bleeding on probing, gingival index, fasting glucose, and the Homeostasis Model Assessment (HOMA2). Results Enrollment was stopped early due to futility. At 6 months, the periodontal therapy group increased HbA1c 0.17% (1.0) (mean (SD)) compared to 0.11% (1.0) in the control group, with no significant difference between groups based on a linear regression model adjusting for clinical site (mean difference = -0.05%; 95% Confidence Interval (CI): -0.23%, 0.12%; p=0.55). Probing depth, clinical attachment loss, bleeding on probing and gingival index measures improved in the treatment group compared to the control group at six months with adjusted between-group differences of 0.33mm (95% CI: 0.26, 0.39), 0

  17. Cloned Hemoglobin Genes Enhance Growth Of Cells

    NASA Technical Reports Server (NTRS)

    Khosla, Chaitan; Bailey, James E.

    1991-01-01

    Experiments show that portable deoxyribonucleic acid (DNA) sequences incorporated into host cells make them produce hemoglobins - oxygen-binding proteins essential to function of red blood cells. Method useful in several biotechnological applications. One, enhancement of growth of cells at higher densities. Another, production of hemoglobin to enhance supplies of oxygen in cells, for use in chemical reactions requiring oxygen, as additive to serum to increase transport of oxygen, and for binding and separating oxygen from mixtures of gases.

  18. Carboxyalkylated Hemoglobin as a Potential Blood Substitute.

    DTIC Science & Technology

    1991-11-19

    diisothiocyanatobenzene sulfonic acid. Collaborative studies with investigators at the Letterman Army Institute of Research indicated that carboxy - methylated hemoglobin... crosslinking agents so that we might find the one with the most desirable properties (2,3). In this annual report, we focus on the reagents studied in...can be considered as a mimic for both of these structures. Crosslinking of Hemoglobin A - In the past year we have sought a better crosslinking agent

  19. Heme degradation upon production of endogenous hydrogen peroxide via interaction of hemoglobin with sodium dodecyl sulfate.

    PubMed

    Salehi, N; Moosavi-Movahedi, A A; Fotouhi, L; Yousefinejad, S; Shourian, M; Hosseinzadeh, R; Sheibani, N; Habibi-Rezaei, M

    2014-04-05

    In this study the hemoglobin heme degradation upon interaction with sodium dodecyl sulfate (SDS) was investigated using UV-vis and fluorescence spectroscopy, multivariate curve resolution analysis, and chemiluminescence method. Our results showed that heme degradation occurred during interaction of hemoglobin with SDS producing three fluorescent components. We showed that the hydrogen peroxide, produced during this interaction, caused heme degradation. In addition, the endogenous hydrogen peroxide was more effective in hemoglobin heme degradation compared to exogenously added hydrogen peroxide. The endogenous form of hydrogen peroxide altered oxyHb to aquamethemoglobin and hemichrome at low concentration. In contrast, the exogenous hydrogen peroxide lacked this ability under same conditions.

  20. Hemoglobin Brisbane: beta68 Leu replaced by His. A new high oxygen affinity variant.

    PubMed

    Brennan, S O; Wells, R M; Smith, H; Carrell, R W

    1981-01-01

    Hemoglobin Brisbane is a new hemoglobin variant which produces a mile erythrocytosis. It is not detectable by electrophoresis at pH 8.6 or by isoelectric focusing but it is mildly unstable and gives a positive result with standard stability tests. The new hemoglobin has increased oxygen affinity and reduced co-operativity with a normal Bohr effect and 2,3-DPG binding. Structural analysis shows that a histidine residue has replaced the leucine normally found at position beta 68 (E12).

  1. Photothermal spectral-domain optical coherence reflectometry for direct measurement of hemoglobin concentration of erythrocytes.

    PubMed

    Yim, Jinyeong; Kim, Hun; Ryu, Suho; Song, Sungwook; Kim, Hyun Ok; Hyun, Kyung-A; Jung, Hyo-Il; Joo, Chulmin

    2014-07-15

    A novel optical detection method for hemoglobin concentration is described. The hemoglobin molecules consisting mainly of iron generate heat upon their absorption of light energy at 532 nm, which subsequently changes the refractive index of the blood. We exploit this photothermal effect to determine the hemoglobin concentration of erythrocytes without any preprocessing of blood. Highly sensitive measurement of refractive index alteration of blood samples is enabled by a spectral-domain low coherence reflectometric sensor with subnanometer-level optical path-length sensitivity. The performance and validity of the sensor are presented by comparing the measured results against the reference data acquired from an automatic hematology analyzer.

  2. Hemoglobin-Based Blood Substitutes and Enhanced Susceptibility to Bacterial Infections

    DTIC Science & Technology

    1994-03-08

    E . coli peritonitis we have determined that DBBF-HB is equally likely as unmodified Hb (on a mole to mole basis) to lead to a fatal outcome in this model. Further investigations were undertaken to elucidate the molecular mechanism of these hemoglobin-driven bacterial infections. The strains of E . coli that exhibit the hemoglobin- adjuvant effect are resistant to phagocytosis by peritoneal macrophages. This feature may explain why hemoglobin is necessary (nutritional iron) but not sufficient for the promotion of E . coli

  3. Noninvasive hemoglobin monitoring: how accurate is enough?

    PubMed

    Rice, Mark J; Gravenstein, Nikolaus; Morey, Timothy E

    2013-10-01

    Evaluating the accuracy of medical devices has traditionally been a blend of statistical analyses, at times without contextualizing the clinical application. There have been a number of recent publications on the accuracy of a continuous noninvasive hemoglobin measurement device, the Masimo Radical-7 Pulse Co-oximeter, focusing on the traditional statistical metrics of bias and precision. In this review, which contains material presented at the Innovations and Applications of Monitoring Perfusion, Oxygenation, and Ventilation (IAMPOV) Symposium at Yale University in 2012, we critically investigated these metrics as applied to the new technology, exploring what is required of a noninvasive hemoglobin monitor and whether the conventional statistics adequately answer our questions about clinical accuracy. We discuss the glucose error grid, well known in the glucose monitoring literature, and describe an analogous version for hemoglobin monitoring. This hemoglobin error grid can be used to evaluate the required clinical accuracy (±g/dL) of a hemoglobin measurement device to provide more conclusive evidence on whether to transfuse an individual patient. The important decision to transfuse a patient usually requires both an accurate hemoglobin measurement and a physiologic reason to elect transfusion. It is our opinion that the published accuracy data of the Masimo Radical-7 is not good enough to make the transfusion decision.

  4. 21 CFR 864.7415 - Abnormal hemoglobin assay.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Abnormal hemoglobin assay. 864.7415 Section 864... hemoglobin assay. (a) Identification. An abnormal hemoglobin assay is a device consisting of the reagents... hemoglobin types. (b) Classification. Class II (performance standards)....

  5. 21 CFR 864.7415 - Abnormal hemoglobin assay.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Abnormal hemoglobin assay. 864.7415 Section 864... hemoglobin assay. (a) Identification. An abnormal hemoglobin assay is a device consisting of the reagents... hemoglobin types. (b) Classification. Class II (performance standards)....

  6. 21 CFR 866.5470 - Hemoglobin immunological test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Hemoglobin immunological test system. 866.5470... Hemoglobin immunological test system. (a) Indentification. A hemoglobin immunological test system is a device... hemoglobin (the oxygen-carrying pigment in red blood cells) in blood, urine, plasma, or other body...

  7. 21 CFR 864.5620 - Automated hemoglobin system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Automated hemoglobin system. 864.5620 Section 864....5620 Automated hemoglobin system. (a) Identification. An automated hemoglobin system is a fully... hemoglobin content of human blood. (b) Classification. Class II (performance standards)....

  8. 21 CFR 864.7500 - Whole blood hemoglobin assays.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Whole blood hemoglobin assays. 864.7500 Section... blood hemoglobin assays. (a) Identification. A whole blood hemoglobin assay is a device consisting or... hemoglobin content of whole blood for the detection of anemia. This generic device category does not...

  9. 21 CFR 864.7415 - Abnormal hemoglobin assay.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Abnormal hemoglobin assay. 864.7415 Section 864... hemoglobin assay. (a) Identification. An abnormal hemoglobin assay is a device consisting of the reagents... hemoglobin types. (b) Classification. Class II (performance standards)....

  10. 21 CFR 864.5620 - Automated hemoglobin system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Automated hemoglobin system. 864.5620 Section 864....5620 Automated hemoglobin system. (a) Identification. An automated hemoglobin system is a fully... hemoglobin content of human blood. (b) Classification. Class II (performance standards)....

  11. 21 CFR 864.7500 - Whole blood hemoglobin assays.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Whole blood hemoglobin assays. 864.7500 Section... blood hemoglobin assays. (a) Identification. A whole blood hemoglobin assay is a device consisting or... hemoglobin content of whole blood for the detection of anemia. This generic device category does not...

  12. 21 CFR 864.7440 - Electrophoretic hemoglobin analysis system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Electrophoretic hemoglobin analysis system. 864....7440 Electrophoretic hemoglobin analysis system. (a) Identification. An electrophoretic hemoglobin... hemoglobin types as an aid in the diagnosis of anemia or erythrocytosis (increased total red cell mass)...

  13. 21 CFR 864.7440 - Electrophoretic hemoglobin analysis system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Electrophoretic hemoglobin analysis system. 864....7440 Electrophoretic hemoglobin analysis system. (a) Identification. An electrophoretic hemoglobin... hemoglobin types as an aid in the diagnosis of anemia or erythrocytosis (increased total red cell mass)...

  14. 21 CFR 864.5620 - Automated hemoglobin system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Automated hemoglobin system. 864.5620 Section 864....5620 Automated hemoglobin system. (a) Identification. An automated hemoglobin system is a fully... hemoglobin content of human blood. (b) Classification. Class II (performance standards)....

  15. 21 CFR 864.7500 - Whole blood hemoglobin assays.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Whole blood hemoglobin assays. 864.7500 Section... blood hemoglobin assays. (a) Identification. A whole blood hemoglobin assay is a device consisting or... hemoglobin content of whole blood for the detection of anemia. This generic device category does not...

  16. 21 CFR 864.7440 - Electrophoretic hemoglobin analysis system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrophoretic hemoglobin analysis system. 864....7440 Electrophoretic hemoglobin analysis system. (a) Identification. An electrophoretic hemoglobin... hemoglobin types as an aid in the diagnosis of anemia or erythrocytosis (increased total red cell mass)...

  17. 21 CFR 864.5620 - Automated hemoglobin system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Automated hemoglobin system. 864.5620 Section 864....5620 Automated hemoglobin system. (a) Identification. An automated hemoglobin system is a fully... hemoglobin content of human blood. (b) Classification. Class II (performance standards)....

  18. 21 CFR 864.7440 - Electrophoretic hemoglobin analysis system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Electrophoretic hemoglobin analysis system. 864....7440 Electrophoretic hemoglobin analysis system. (a) Identification. An electrophoretic hemoglobin... hemoglobin types as an aid in the diagnosis of anemia or erythrocytosis (increased total red cell mass)...

  19. 21 CFR 866.5470 - Hemoglobin immunological test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hemoglobin immunological test system. 866.5470... Hemoglobin immunological test system. (a) Indentification. A hemoglobin immunological test system is a device... hemoglobin (the oxygen-carrying pigment in red blood cells) in blood, urine, plasma, or other body...

  20. 21 CFR 866.5470 - Hemoglobin immunological test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Hemoglobin immunological test system. 866.5470... Hemoglobin immunological test system. (a) Indentification. A hemoglobin immunological test system is a device... hemoglobin (the oxygen-carrying pigment in red blood cells) in blood, urine, plasma, or other body...

  1. 21 CFR 864.5620 - Automated hemoglobin system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Automated hemoglobin system. 864.5620 Section 864....5620 Automated hemoglobin system. (a) Identification. An automated hemoglobin system is a fully... hemoglobin content of human blood. (b) Classification. Class II (performance standards)....

  2. 21 CFR 864.7415 - Abnormal hemoglobin assay.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Abnormal hemoglobin assay. 864.7415 Section 864... hemoglobin assay. (a) Identification. An abnormal hemoglobin assay is a device consisting of the reagents... hemoglobin types. (b) Classification. Class II (performance standards)....

  3. 21 CFR 864.7500 - Whole blood hemoglobin assays.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Whole blood hemoglobin assays. 864.7500 Section... blood hemoglobin assays. (a) Identification. A whole blood hemoglobin assay is a device consisting or... hemoglobin content of whole blood for the detection of anemia. This generic device category does not...

  4. 21 CFR 866.5470 - Hemoglobin immunological test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Hemoglobin immunological test system. 866.5470... Hemoglobin immunological test system. (a) Indentification. A hemoglobin immunological test system is a device... hemoglobin (the oxygen-carrying pigment in red blood cells) in blood, urine, plasma, or other body...

  5. 21 CFR 864.7500 - Whole blood hemoglobin assays.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Whole blood hemoglobin assays. 864.7500 Section... blood hemoglobin assays. (a) Identification. A whole blood hemoglobin assay is a device consisting or... hemoglobin content of whole blood for the detection of anemia. This generic device category does not...

  6. 21 CFR 864.7415 - Abnormal hemoglobin assay.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Abnormal hemoglobin assay. 864.7415 Section 864... hemoglobin assay. (a) Identification. An abnormal hemoglobin assay is a device consisting of the reagents... hemoglobin types. (b) Classification. Class II (performance standards)....

  7. 21 CFR 864.7440 - Electrophoretic hemoglobin analysis system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Electrophoretic hemoglobin analysis system. 864....7440 Electrophoretic hemoglobin analysis system. (a) Identification. An electrophoretic hemoglobin... hemoglobin types as an aid in the diagnosis of anemia or erythrocytosis (increased total red cell mass)...

  8. Tangential flow filtration of hemoglobin.

    PubMed

    Palmer, Andre F; Sun, Guoyong; Harris, David R

    2009-01-01

    Bovine and human hemoglobin (bHb and hHb, respectively) was purified from bovine and human red blood cells via tangential flow filtration (TFF) in four successive stages. TFF is a fast and simple method to purify Hb from RBCs using filtration through hollow fiber (HF) membranes. Most of the Hb was retained in stage III (100 kDa HF membrane) and displayed methemoglobin levels less than 1%, yielding final concentrations of 318 and 300 mg/mL for bHb and hHb, respectively. Purified Hb exhibited much lower endotoxin levels than their respective RBCs. The purity of Hb was initially assessed via SDS-PAGE, and showed tiny impurity bands for the stage III retentate. The oxygen affinity (P(50)) and cooperativity coefficient (n) were regressed from the measured oxygen-RBC/Hb equilibrium curves of RBCs and purified Hb. These results suggest that TFF yielded oxygen affinities of bHb and hHb that are comparable to values in the literature. LC-MS was used to measure the molecular weight of the alpha (alpha) and beta (beta) globin chains of purified Hb. No impurity peaks were present in the HPLC chromatograms of purified Hb. The mass of the molecular ions corresponding to the alpha and beta globin chains agreed well with the calculated theoretical mass of the alpha- and beta- globin chains. Taken together, our results demonstrate that HPLC-grade Hb can be generated via TFF. In general, this method can be more broadly applied to purify Hb from any source of RBCs. This work is significant, since it outlines a simple method for generating Hb for synthesis and/or formulation of Hb-based oxygen carriers.

  9. Formation of mammalian erythrocytes: chromatin condensation and enucleation.

    PubMed

    Ji, Peng; Murata-Hori, Maki; Lodish, Harvey F

    2011-07-01

    In all vertebrates, the cell nucleus becomes highly condensed and transcriptionally inactive during the final stages of red cell biogenesis. Enucleation, the process by which the nucleus is extruded by budding off from the erythroblast, is unique to mammals. Enucleation has critical physiological and evolutionary significance in that it allows an elevation of hemoglobin levels in the blood and also gives red cells their flexible biconcave shape. Recent experiments reveal that enucleation involves multiple molecular and cellular pathways that include histone deacetylation, actin polymerization, cytokinesis, cell-matrix interactions, specific microRNAs and vesicle trafficking; many evolutionarily conserved proteins and genes have been recruited to participate in this uniquely mammalian process. In this review, we discuss recent advances in mammalian erythroblast chromatin condensation and enucleation, and conclude with our perspectives on future studies.

  10. Discovery of the magnetic behavior of hemoglobin: A beginning of bioinorganic chemistry

    PubMed Central

    Bren, Kara L.; Eisenberg, Richard; Gray, Harry B.

    2015-01-01

    Two articles published by Pauling and Coryell in PNAS nearly 80 years ago described in detail the magnetic properties of oxy- and deoxyhemoglobin, as well as those of closely related compounds containing hemes. Their measurements revealed a large difference in magnetism between oxygenated and deoxygenated forms of the protein and, along with consideration of the observed diamagnetism of the carbonmonoxy derivative, led to an electronic structural formulation of oxyhemoglobin. The key role of hemoglobin as the main oxygen carrier in mammalian blood had been established earlier, and its allosteric behavior had been described in the 1920s. The Pauling–Coryell articles on hemoglobin represent truly seminal contributions to the field of bioinorganic chemistry because they are the first to make connections between active site electronic structure and the function of a metalloprotein. PMID:26508205

  11. Hemoglobin Status and Externalizing Behavioral Problems in Children

    PubMed Central

    Su, Jianhua; Cui, Naixue; Zhou, Guoping; Ai, Yuexian; Sun, Guiju; Zhao, Sophie R.; Liu, Jianghong

    2016-01-01

    Background: Still considered one of the most prevalent nutritional problems in the world, anemia has been shown in many studies to have deleterious effects on neurobehavioral development. While most research efforts have focused on investigating the effects of anemia on social and emotional development of infants by using a cross-sectional design, research is still needed to investigate whether early childhood anemia, beyond infantile years, is linked with behavioral problems. Objective: This study assessed whether (1) hemoglobin (Hb) levels in early childhood are associated with externalizing behavior; and (2) this relationship is confounded by social adversity. Methods: Hemoglobin levels were taken from children (N = 98) of the China Jintan Cohort Study at age 4 years, and externalizing behaviors (attention and aggression) were assessed with the Child Behavior Checklist (ASEBA-CBCL) at age 6 years (mean age 5.77 ± 0.39 years old). Results: Compared with other children in the sample, children with relatively lower Hb levels at age 4 had more behavioral problems in both attention and aggression at age 6, independent of social adversity. For boys, this association was significant for attention problems, which did not interact with social adversity. For girls, the association was significant for aggression, which interacted with social adversity. While girls on average exhibited higher social adversity than boys, the main effect of Hb was only significant in girls with low social adversity. Conclusions: These results indicate that there is an inverse association between hemoglobin levels and later behavioral problems. Findings of this study suggest that regular monitoring of children’s hemoglobin levels and appropriate intervention may help with early identification of behavioral problems. PMID:27472352

  12. Evolutionary paths to mammalian cochleae.

    PubMed

    Manley, Geoffrey A

    2012-12-01

    Evolution of the cochlea and high-frequency hearing (>20 kHz; ultrasonic to humans) in mammals has been a subject of research for many years. Recent advances in paleontological techniques, especially the use of micro-CT scans, now provide important new insights that are here reviewed. True mammals arose more than 200 million years (Ma) ago. Of these, three lineages survived into recent geological times. These animals uniquely developed three middle ear ossicles, but these ossicles were not initially freely suspended as in modern mammals. The earliest mammalian cochleae were only about 2 mm long and contained a lagena macula. In the multituberculate and monotreme mammalian lineages, the cochlea remained relatively short and did not coil, even in modern representatives. In the lineage leading to modern therians (placental and marsupial mammals), cochlear coiling did develop, but only after a period of at least 60 Ma. Even Late Jurassic mammals show only a 270 ° cochlear coil and a cochlear canal length of merely 3 mm. Comparisons of modern organisms, mammalian ancestors, and the state of the middle ear strongly suggest that high-frequency hearing (>20 kHz) was not realized until the early Cretaceous (~125 Ma). At that time, therian mammals arose and possessed a fully coiled cochlea. The evolution of modern features of the middle ear and cochlea in the many later lineages of therians was, however, a mosaic and different features arose at different times. In parallel with cochlear structural evolution, prestins in therian mammals evolved into effective components of a new motor system. Ultrasonic hearing developed quite late-the earliest bat cochleae (~60 Ma) did not show features characteristic of those of modern bats that are sensitive to high ultrasonic frequencies.

  13. Polyethylene Glycol Camouflaged Earthworm Hemoglobin

    PubMed Central

    Moges, Selamawit; Nacharaju, Parimala; Roche, Camille; Dantsker, David; Palmer, Andre; Friedman, Joel M.

    2017-01-01

    Nearly 21 million components of blood and whole blood and transfused annually in the United States, while on average only 13.6 million units of blood are donated. As the demand for Red Blood Cells (RBCs) continues to increase due to the aging population, this deficit will be more significant. Despite decades of research to develop hemoglobin (Hb) based oxygen (O2) carriers (HBOCs) as RBC substitutes, there are no products approved for clinical use. Lumbricus terrestris erythrocruorin (LtEc) is the large acellular O2 carrying protein complex found in the earthworm Lumbricus terrestris. LtEc is an extremely stable protein complex, resistant to autoxidation, and capable of transporting O2 to tissue when transfused into mammals. These characteristics render LtEc a promising candidate for the development of the next generation HBOCs. LtEc has a short half-life in circulation, limiting its application as a bridge over days, until blood became available. Conjugation with polyethylene glycol (PEG-LtEc) can extend LtEc circulation time. This study explores PEG-LtEc pharmacokinetics and pharmacodynamics. To study PEG-LtEc pharmacokinetics, hamsters instrumented with the dorsal window chamber were subjected to a 40% exchange transfusion with 10 g/dL PEG-LtEc or LtEc and followed for 48 hours. To study the vascular response of PEG-LtEc, hamsters instrumented with the dorsal window chamber received multiple infusions of 10 g/dL PEG-LtEc or LtEc solution to increase plasma LtEc concentration to 0.5, then 1.0, and 1.5 g/dL, while monitoring the animals’ systemic and microcirculatory parameters. Results confirm that PEGylation of LtEc increases its circulation time, extending the half-life to 70 hours, 4 times longer than that of unPEGylated LtEc. However, PEGylation increased the rate of LtEc oxidation in vivo. Vascular analysis verified that PEG-LtEc showed the absence of microvascular vasoconstriction or systemic hypertension. The molecular size of PEG-LtEc did not change the

  14. The Electrophoretic Pattern of Hemoglobin in Newborn Babies, and Abnormalities of Hemoglobin F Synthesis in Adults

    PubMed Central

    Vella, F.; Cunningham, T. A.

    1967-01-01

    On routine electrophoretic analyses on filter paper and starch gel in an alkaline or neutral medium, no abnormal hemoglobin fractions were found in the blood of 600 newborn infants or their mothers. Trace amounts of hemoglobin Barts were noted in many of the blood samples from newborns when the starch gels (phosphate buffer pH 7.0) were stained with a benzidine/H2O2 reagent. In one infant, precocious cessation of synthesis of hemoglobin F was postulated to account for the small amounts of this hemoglobin found in a cord-blood specimen. Analysis of 15,000 blood samples from adults revealed two instances in which the hemoglobin F level was 20 and 35%, respectively. The former was attributed to a hereditary persistence of hemoglobin F, while the latter was associated with acute leukemia. In an addendum, the finding of an infant with an abnormal hemoglobin variant, resembling in many of its properties hemoglobin F Texas, is reported. ImagesFig. 1Fig. 2 PMID:6019054

  15. Predictable convergence in hemoglobin function has unpredictable molecular underpinnings.

    PubMed

    Natarajan, Chandrasekhar; Hoffmann, Federico G; Weber, Roy E; Fago, Angela; Witt, Christopher C; Storz, Jay F

    2016-10-21

    To investigate the predictability of genetic adaptation, we examined the molecular basis of convergence in hemoglobin function in comparisons involving 56 avian taxa that have contrasting altitudinal range limits. Convergent increases in hemoglobin-oxygen affinity were pervasive among high-altitude taxa, but few such changes were attributable to parallel amino acid substitutions at key residues. Thus, predictable changes in biochemical phenotype do not have a predictable molecular basis. Experiments involving resurrected ancestral proteins revealed that historical substitutions have context-dependent effects, indicating that possible adaptive solutions are contingent on prior history. Mutations that produce an adaptive change in one species may represent precluded possibilities in other species because of differences in genetic background.

  16. MP4, a vasodilatory PEGylated hemoglobin.

    PubMed

    Cole, Russell H; Vandegriff, Kim D

    2011-01-01

    A vasodilatory hemoglobin (Hb)-based O(2) carrier (HBOC) has been developed by surface conjugation polyethylene glycol to tetrameric human Hb (MP4, Sangart, San Diego). Because the NO-binding kinetics of MP4 are similar to vasoconstrictive HBOCs, we propose that the decoupling of NO scavenging from vascular response is a consequence of MP4's high O(2) affinity (p50 = 5 mmHg) and unique surface chemistry. The release of ATP from erythrocytes is vasodilatory and the application of a high O(2) affinity HBOC minimizes ATP interference with intravascular ATP signaling. A second potential mechanism of action for MP4 involves the surface conjugation of polyethylene glycol (PEG) to tetrameric human Hb. It has been shown that the addition of unconjugated high molecular weight (Mw) PEG to cultured lung endothelial cells causes an immediate and significant reduction in endothelial permeability; an effect opposite to that of endothelial agonists such as cell-free Hb. It appears that some of the benefits of the PEG-endothelium interaction are carried onto molecules such as PEGylated Hb and PEGylated albumin, as demonstrated by favorable hemodynamic responses in vivo. PEGylation of ß93 cysteine residues, as in MP4, has also been reported to increase the nitrite reductase activity of Hb and enhance conversion of endogenous nitrite to bioactive NO.

  17. The effect of 3,4-methylenedioxymethamphetamine ('Ecstasy') on serotonergic regulation of the mammalian circadian clock mechanism in rats: the role of dopamine and hyperthermia.

    PubMed

    Dafters, Richard I; Biello, Stephany M

    2003-10-23

    The recreational drug 3,4-methylenedioxymethamphetamine (MDMA) is known to be a neurotoxin for serotonergic axons ascending from the raphe nucleus including those which terminate on neurons of the suprachiasmatic nuclei (SCN) of the hypothalamus, the putative mammalian circadian clock. Since dopamine release has been implicated in the serotonergic neurotoxicity, we examined the effects of the dopamine synthesis inhibitor alpha-methyl-p-tyrosine (AMPT) and the D2 receptor antagonist haloperidol (HAL) on the long-term effect of MDMA on serotonergic regulation of the SCN neuronal firing rhythm. Co-administration of AMPT or HAL with MDMA eliminated the acute hyperthermic response but had no effect on the MDMA-induced phase shift in the firing rhythm of SCN neurons to the selective 5-HT1A receptor agonist, 8-hydroxy-2-(dipropylamino)-tetralin. It is concluded that neither dopamine metabolism nor hyperthermia account for the altered serotonergic function in the SCN produced by MDMA. Toxic free radical production following MDMA metabolism may be responsible.

  18. Oxygen binding properties of hemoglobin from the white rhinoceros (beta 2-GLU) and the tapir.

    PubMed

    Baumann, R; Mazur, G; Braunitzer, G

    1984-04-01

    The beta-chain of rhinoceros hemoglobin contains glutamic acid at position beta 2, and important site for the binding of organic phosphates. We have investigated the oxygen binding properties of this hemoglobin and its interaction with ATP, 2,3-diphosphoglycerate, CO2 and chloride. The results show that the presence of GLU at position beta 2 nearly abolishes the effect of organic phosphates and CO2, whereas the oxygen-linked binding of chloride is not affected. Thus rhinoceros hemoglobin has only protons and chloride anions as major allosteric effectors for the control of its oxygen affinity. From the results obtained with hemoglobin solutions it can be calculated that the blood oxygen affinity of the rhinoceros must be rather high with a P50 of about 20 torr at pH 7.4 and 37 degrees C, which conforms with observations obtained for other large mammals.

  19. Hemoglobin concentration determination based on near infrared spatially resolved transmission spectra

    NASA Astrophysics Data System (ADS)

    Zhang, Linna; Li, Gang; Lin, Ling

    2016-10-01

    Spatially resolved diffuse reflectance spectroscopy method has been proved to be more effective than single point spectroscopy method in the experiment to predict the concentration of the Intralipid diluted solutions. However, Intralipid diluted solution is simple, cannot be the representative of turbid liquids. Blood is a natural and meaningful turbid liquid, more complicate. Hemoglobin is the major constituent of the whole blood. And hemoglobin concentration is commonly used in clinical medicine to diagnose many diseases. In this paper, near infrared spatially resolved transmission spectra (NIRSRTS) and Partial Least Square Regression (PLSR) were used to predict the hemoglobin concentration of human blood. The results showed the prediction ability for hemoglobin concentration of the proposed method is better than single point transmission spectroscopy method. This paper demonstrated the feasibility of the spatially resolved diffuse reflectance spectroscopy method for practical liquid composition analysis. This research provided a new thinking of practical turbid liquid composition analysis.

  20. The interaction of C.I. acid red 27 with human hemoglobin in solution.

    PubMed

    Wang, Yan-Qing; Zhang, Hong-Mei; Tang, Bo-Ping

    2010-08-02

    The nature of the interaction between human hemoglobin and C.I. acid red 27 was investigated systematically by ultraviolet-vis absorbance, circular dichroism, fluorescence, synchronous fluorescence, and three-dimensional fluorescence spectra techniques at pH 7.40. The quenching mechanism, binding constants, and the number of binding sites were determined by the quenching of human hemoglobin fluorescence in presence of C.I. acid red 27. The results showed that the nature of the quenching was of static type and the process of binding acid red 27 on human hemoglobin was a spontaneous molecular interaction procedure. The electrostatic and hydrophobic interactions played a major role in stabilizing the complex; The distance r between donor and acceptor was obtained to be 4.40 nm according to Förster's theory; The effect of acid red 27 on the conformation of human hemoglobin was analyzed using synchronous fluorescence, circular dichroism and three-dimensional fluorescence spectra.

  1. Analysis of the binding interaction in uric acid - Human hemoglobin system by spectroscopic techniques.

    PubMed

    Makarska-Bialokoz, Magdalena

    2017-01-31

    The binding interaction between human hemoglobin and uric acid has been studied for the first time, by UV-vis absorption and steady-state, synchronous and three-dimensional fluorescence techniques. Characteristic effects observed for human hemoglobin intrinsic fluorescence during interaction with uric acid at neutral pH point at the formation of stacking non-covalent and non-fluorescent complexes. All the calculated parameters, the binding, fluorescence quenching and bimolecular quenching rate constants, as well as Förster resonance energy transfer parameters confirm the existence of static quenching. The results of synchronous fluorescence measurements indicate that the fluorescence quenching of human hemoglobin originates both from Trp and Tyr residues and that the addition of uric acid could significantly hinder the physiological functions of human hemoglobin.

  2. Evaluation of the role hemoglobin in cerebrospinal fluid plays in producing contractions of cerebral arteries.

    PubMed

    White, R P; Macleod, R M; Muhlbauer, M S

    1987-03-01

    Many investigators have concluded that hemoglobin is the spasmogen responsible for cerebral vasospasm. The present study was designed to ascertain whether the contractile responses of isolated canine basilar arteries to xanthochromic cerebrospinal fluid from subarachnoid hemorrhage patients was associated with hemoglobin concentration as measured spectrophotometrically. The results clearly showed that spasmogenicity and hemoglobin content were not correlated. The magnitude and duration of the arterial responses varied greatly, further indicating that more than a single factor was responsible. The potent antagonistic, vasodilator effect of such proteins as antithrombin III may account for some of the variation, but the results directly complement clinical findings of others indicating that hemoglobin is not the singular cause of cerebral vasospasm.

  3. Effects of Chromosomal Integration of the Vitreoscilla Hemoglobin Gene (vgb) and S-Adenosylmethionine Synthetase Gene (metK) on ε-Poly-L-Lysine Synthesis in Streptomyces albulus NK660.

    PubMed

    Gu, Yanyan; Wang, Xiaomeng; Yang, Chao; Geng, Weitao; Feng, Jun; Wang, Yuanyuan; Wang, Shufang; Song, Cunjiang

    2016-04-01

    ε-Poly-L-lysine (ε-PL) is a widely used natural food preservative. To test the effects of the Vitreoscilla hemoglobin (VHb) and S-adenosylmethionine (SAM) on ε-PL synthesis in Streptomyces albulus NK660, the heterologous VHb gene (vgb) and SAM synthetase gene (metK) were inserted into the S. albulus NK660 chromosome under the control of the constitutive ermE* promoter. CO-difference spectrum analysis showed S. albulus NK660-VHb strain could express functional VHb. S. albulus NK660-VHb produced 26.67 % higher ε-PL and 14.57 % higher biomass than the wild-type control, respectively. Reversed-phase high-pressure liquid chromatography (RP-HPLC) results showed the overexpression of the metK gene resulted in increased intracellular SAM synthesis in S. albulus NK660-SAM, which caused increases of biomass as well as the transcription level of ε-PL synthetase gene (pls). Results indicated that the expression of vgb and metK gene improved on ε-PL synthesis and biomass for S. albulus NK660, respectively.

  4. Effect of dietary polyphenols from hop (Humulus lupulus L.) pomace on adipose tissue mass, fasting blood glucose, hemoglobin A1c, and plasma monocyte chemotactic protein-1 levels in OLETF rats.

    PubMed

    Yui, Kazuki; Uematsu, Hiroki; Muroi, Keisuke; Ishii, Kazuhiro; Baba, Minako; Osada, Kyoichi

    2013-01-01

    Hop (Humulus lupulus L.) pomace contains procyanidin-rich polyphenols, which are large oligomeric compounds of catechin. We studied the effect of high dose (1%) of dietary hop pomace polyphenols (HPs) in Otsuka Long-EvansTokushima Fatty (OLETF) rats, an animal model of type 2 diabetes. By 70 days, the rats fed HPs tended to have a lower body weight and reduced mesenteric white adipose tissue weight than the rats fed a control diet. Triglyceride levels in both plasma and liver tended to be lower in the HPs-fed group than in the control group. Dietary HPs substantially suppressed the activities of hepatic fatty acid synthetase, glucose-6-phosphate dehydrogenase, and malic enzyme, through the suppression of SREBP1c mRNA expression in OLETF rats. Moreover, in the HPs-fed group, monocyte chemotactic protein-1 (MCP-1) expression and fasting blood glucose levels at 40 days, and hemoglobin A1c (HbA1c) levels at 70 days were significantly lower than those in the control group. Thus, dietary HPs may exert an ameliorative function on hepatic fatty acid metabolism, glucose metabolism, and inflammatory response accompanying the increase of the adipose tissue mass in OLETF rats.

  5. Mammalian glycosylation in immunity.

    PubMed

    Marth, Jamey D; Grewal, Prabhjit K

    2008-11-01

    Glycosylation produces a diverse and abundant repertoire of glycans, which are collectively known as the glycome. Glycans are one of the four fundamental macromolecular components of all cells, and are highly regulated in the immune system. Their diversity reflects their multiple biological functions that encompass ligands for proteinaceous receptors known as lectins. Since the discovery that selectins and their glycan ligands are important for the regulation of leukocyte trafficking, it has been shown that additional features of the vertebrate immune system are also controlled by endogenous cellular glycosylation. This Review focuses on the emerging immunological roles of the mammalian glycome.

  6. Classification of the Disorders of Hemoglobin

    PubMed Central

    Forget, Bernard G.; Bunn, H. Franklin

    2013-01-01

    Over the years, study of the disorders of hemoglobin has served as a paradigm for gaining insights into the cellular and molecular biology, as well as the pathophysiology, of inherited genetic disorders. To date, more than 1000 disorders of hemoglobin synthesis and/or structure have been identified and characterized. Study of these disorders has established the principle of how a mutant genotype can alter the function of the encoded protein, which in turn can lead to a distinct clinical phenotype. Genotype/phenotype correlations have provided important understanding of pathophysiological mechanisms of disease. Before presenting a brief overview of these disorders, we provide a summary of the structure and function of hemoglobin, along with the mechanism of assembly of its subunits, as background for the rationale and basis of the different categories of disorders in the classification. PMID:23378597

  7. A rare hemoglobin variant, Hb Belliard

    PubMed Central

    Benavides, Raul

    2017-01-01

    There are many documented variants of hemoglobin; however, other than a limited number (such as sickle cell disease), very few are known to have any clinical significance. As advances in detection and identification continue through gel electrophoresis, capillary electrophoresis, and DNA sequencing, more rare variants are identified. Without case reporting, the significance of these variants will remain unknown or continue to be thought of as insignificant. Here we report a rare hemoglobin variant, Hb Belliard, which was detected in a 68-year-old Indian immigrant to the United States. He presented with elevated hemoglobin and was found to have a unique peak on capillary electrophoresis. The specimen was sent for sequencing and was subsequently found to have Hb Belliard. Currently, Hb Belliard is thought to be insignificant.

  8. Site-specific semisynthetic variant of human hemoglobin

    SciTech Connect

    Hefta, S.A.; Lyle, S.B.; Busch, M.R.; Harris, D.E.; Matthew, J.B.; Gurd, F.R.N.

    1988-02-01

    A single round of Edman degradation was employed to remove the NH/sub 2/-terminal valine from isolated ..cap alpha.. chains of human hemoglobin. Reconstitution of normal ..beta.. chains with truncated or substituted ..cap alpha.. chains was used to form truncated (des-Val/sup 1/-..cap alpha..1) and substituted (((1-/sup 13/C)Gly/sup 1/)..cap alpha..1) tetrameric hemoglobin analogs. Structural homology of the analogs with untreated native hemoglobin was established by using several spectroscopic and physical methods. Functional studies indicate that the reconstituted tetrameric protein containing des-Val/sup 1/-..cap alpha.. chains has a higher affinity for oxygen, is less influenced by chloride ions or 2,3-biphosphoglycerate, and shows lower cooperativity than native hemoglobin. These results confirm the key functional role of the ..cap alpha..-chain NH/sub 2/ terminus in mediating cooperative oxygen binding across the dimer interface. The NH/sub 2/-terminal pK/sub 1/2/ value was determined for the (/sup 13/C)glycine-substituted analog to be 7.46 +/- 0.09 at 15/sup 0/C in the carbon monoxide-liganded form. This value, measured directly by /sup 13/C NMR, agrees with the determination made by the less-direct /sup 13/CO/sub 2/ method and confirms the role of this residue as a contributor to the alkaline Bohr effect; however, it is consistent with the presence of an NH/sub 2/-terminal salt bridge to the carboxylate of Arg-141 of the ..cap alpha.. chain in the liganded form.

  9. Mammalian Toxicity of Munitions Compounds. Phase II. Effects of Multiple Doses Part II. 2,4-Dinitrotoluene

    DTIC Science & Technology

    1978-11-01

    II: Effects of Multiple Doses Part !I: 2,4-T)initrotoiuene I Progres Report No. 3 oNovember 1978 by 3I Cheng-Chun Lee U Hirty V. Ellis, III Jo.,n J...Sciences Division November 1978 vii :. •I~~~~AMMALIAN TOXICITY OF MUNITIONS COMPOUNDS ... ... PHASE IIz Effects of Multiple Doses m . ............... PART...161 xi MAMOMALIAN TOXICITY OF MUNITION COMPOUNDS PHASE II: Effects of Multiple Dones PART II: 2,4

  10. Hemoglobin dynamics in red blood cells: correlation to body temperature.

    PubMed

    Stadler, A M; Digel, I; Artmann, G M; Embs, J P; Zaccai, G; Büldt, G

    2008-12-01

    A transition in hemoglobin behavior at close to body temperature has been discovered recently by micropipette aspiration experiments on single red blood cells (RBCs) and circular dichroism spectroscopy on hemoglobin solutions. The transition temperature was directly correlated to the body temperatures of a variety of species. In an exploration of the molecular basis for the transition, we present neutron scattering measurements of the temperature dependence of hemoglobin dynamics in whole human RBCs in vivo. The data reveal a change in the geometry of internal protein motions at 36.9 degrees C, at human body temperature. Above that temperature, amino acid side-chain motions occupy larger volumes than expected from normal temperature dependence, indicating partial unfolding of the protein. Global protein diffusion in RBCs was also measured and the findings compared favorably with theoretical predictions for short-time self-diffusion of noncharged hard-sphere colloids. The results demonstrated that changes in molecular dynamics in the picosecond time range and angstrom length scale might well be connected to a macroscopic effect on whole RBCs that occurs at body temperature.

  11. Geminate combination of oxygen with iron-cobalt hybrid hemoglobins.

    PubMed

    Morris, R J; Gibson, Q H; Ikeda-Saito, M; Yonetani, T

    1984-06-10

    Photodissociation of oxygen from the ferrous subunits of hybrid hemoglobins in which the heme of either the alpha or the beta chain has been replaced by cobalt protoporphyrin IX shows large differences between the subunits. With a 25-ns light pulse, the apparent quantum yield at the end of the flash is greater for the beta-iron hybrid than for the alpha-iron hybrid. With the beta-iron hybrid, the yield is greater when solution conditions favor the T-state. After the flash, a part of the oxygen which has been dissociated recombines with a half-time of the order of tens of nanoseconds. The proportion is greatest in the R-state at low temperature and least in the T-state. With the alpha-iron hybrid, oxygen is much less readily removed, and the rapid recombination is slight or absent. It is seen most clearly at low temperatures in conditions which favor the T-state. The long term (greater than 100 ns) effect is that oxygen is much more readily removed from the beta-iron hybrid in the T-state than under any other condition. Analogous flash experiments performed with human hemoglobin A may be closely simulated by superposition of the results obtained with the two hybrid hemoglobins under the same conditions. Isolated human alpha and beta--SH chains show differences similar to, but less marked than, those of the iron-cobalt hybrids.

  12. Application of glycated hemoglobin in the perinatal period

    PubMed Central

    Yu, Haiyan; Qi, Xiaorong; Wang, Xiaodong

    2014-01-01

    Glycated hemoglobin (HbA1c) is a special fragment formed by the binding of glucose to the C chain or D chain of hemoglobin A and as a result of non-enzymatic catalysis of mature hemoglobin and glucose, which is an indicator used to evaluate the blood glucose control in diabetes mellitus (DM) patients. Recent researches indicated that HbA1c could be applied in gestational diabetes mellitus (GDM) and pregnancy combined DM, and increasing of HbA1c was close associated with adverse outcomes of women with pregnancy combined DM and GDM. HbA1c was reported to have a significant importance in monitoring congenital malformation, abortion, perinatal mortality, preeclampsia, postpartum abnormal glucose metabolism, vascular complications and so on, which could be a test item during the second trimester. Sensitivity of HbA1c in diagnoses of DM is lower than oral glucose tolerance test (OGTT), thus OGTT is still the golden standard of GDM. Emphasis should be put on standardization of detection and threshold of HbA1c and establishment of HbA1c normal ranges of different trimesters, when HbA1c is used to diagnose pregnancy combined DM and GDM, and evaluate effects of treatments. PMID:25663962

  13. Archetype, adaptation and the mammalian heart.

    PubMed

    Meijler, F L; Meijler, T D

    2011-03-01

    Forty years ago, we started our quest for 'The Holy Grail' of understanding ventricular rate control and rhythm in atrial fibrillation (AF). We therefore studied the morphology and function of a wide range of mammalian hearts. From mouse to whale, we found that all hearts show similar structural and functional characteristics. This suggests that the mammalian heart remained well conserved during evolution and in this aspect it differs from other organs and parts of the mammalian body. The archetype of the mammalian heart was apparently so successful that adaptation by natural selection (evolution) caused by varying habitat demands, as occurred in other organs and many other aspects of mammalian anatomy, bypassed the heart. The structure and function of the heart of placental mammals have thus been strikingly conserved throughout evolution. The changes in the mammalian heart that did take place were mostly adjustments (scaling), to compensate for variations in body size and shape. A remarkable scaling effect is, for instance, the difference in atrioventricular (AV) conduction time, which is vital for optimal cardiac function in all mammals, small and large. Scaling of AV conduction takes place in the AV node (AVN), but its substrate is unknown. This sheds new light on the vital role of the AVN in health and disease. The AVN is master and servant of the heart at the same time and is of salient importance for our understanding of supraventricular arrhythmias in humans, especially AF. In Information Technology a software infra-structure called 'enterprise service bus' (ESB) may provide understanding of the mammalian heart's conservation during evolution. The ESB is quite unspecific (and thus general) when compared with the specialised components it has to support. For instance, one of the functions of an ESB is the routing of messages between system nodes. This routing is independent and unaware of the content of the messages. The function of the heart is likewise

  14. Investigation of Hemoglobin/Gold Nanoparticle Heterolayer on Micro-Gap for Electrochemical Biosensor Application

    PubMed Central

    Lee, Taek; Kim, Tae-Hyung; Yoon, Jinho; Chung, Yong-Ho; Lee, Ji Young; Choi, Jeong-Woo

    2016-01-01

    In the present study, we fabricated a hemoglobin/gold nanoparticle (Hb/GNP) heterolayer immobilized on the Au micro-gap to confirm H2O2 detection with a signal-enhancement effect. The hemoglobin which contained the heme group catalyzed the reduction of H2O2. To facilitate the electron transfer between hemoglobin and Au micro-gap electrode, a gold nanoparticle was introduced. The Au micro-gap electrode that has gap size of 5 µm was fabricated by conventional photolithographic technique to locate working and counter electrodes oppositely in a single chip for the signal sensitivity and reliability. The hemoglobin was self-assembled onto the Au surface via chemical linker 6-mercaptohexanoic acid (6-MHA). Then, the gold nanoparticles were adsorbed onto hemoglobin/6-MHA heterolayers by the layer-by-layer (LbL) method. The fabrication of the Hb/GNP heterolayer was confirmed by atomic force microscopy (AFM) and surface-enhanced Raman spectroscopy (SERS). The redox property and H2O2 detection of Hb/GNP on the micro-gap electrode was investigated by a cyclic voltammetry (CV) experiment. Taken together, the present results show that the electrochemical signal-enhancement effect of a hemoglobin/nanoparticle heterolayer was well confirmed on the micro-scale electrode for biosensor applications. PMID:27171089

  15. Low concentration of exogenous carbon monoxide protects mammalian cells against proliferation induced by radiation-induced bystander effect.

    PubMed

    Tong, Liping; Yu, K N; Bao, Lingzhi; Wu, Wenqing; Wang, Hongzhi; Han, Wei

    2014-01-01

    Radiation-induced bystander effect (RIBE) has been proposed to have tight relationship with the irradiation-caused secondary cancers beyond the irradiation-treated area after radiotherapy. Our previous studies demonstrated a protective effect of low concentration carbon monoxide (CO) on the genotoxicity of RIBE after α-particle irradiation. In the present work, a significant inhibitory effect of low-dose exogenous CO, generated by tricarbonyldichlororuthenium (II) dimer [CO-releasing molecule (CORM-2)], on both RIBE-induced proliferation and chromosome aberration was observed. Further studies on the mechanism revealed that the transforming growth factor β1/nitric oxide (NO) signaling pathway, which mediated RIBE signaling transduction, could be modulated by CO involved in the protective effects. Considering the potential of exogenous CO in clinical applications and its protective effect on RIBE, the present work aims to provide a foundation for potential application of CO in radiotherapy.

  16. Comparison of S9 mix and hepatocytes as external metabolizing systems in mammalian cell cultures: cytogenetic effects of 7,12-dimethylbenzanthracene and aflatoxin B1

    SciTech Connect

    Madle, E.; Tiedemann, G.; Madle, S.; Oett, A.; Kaufmann, G.

    1986-01-01

    Two external metabolizing systems, S9 mix from Aroclor-induced rat livers and freshly isolated hepatocytes, were used for activation in cultures of human lymphocytes and V79 cells. 7, 12-dimethylbenzanthracene (DMBA) and aflatoxin B1 (AFB1) were employed as indirectly acting reference mutagens. Mutagenic effects were measured by induction of sister chromatid exchange (SCE). With DMBA, SCE-inducing effects were found to be quite similar after activation by S9 mix and activation by hepatocytes. In contrast with AFB1, S9 activation led to a stronger SCE induction than hepatocyte activation in both target cells. The induction of chromosomal aberrations by AFB1 after activation by the two metabolizing systems was also analyzed in V79 cells. This experiment again revealed that AFB1 was more efficiently activated by S9 mix than by hepatocytes. The experiments have shown that the suitability of hepatocytes as an activation system is not restricted to microbial or eukaryotic point mutation assays, but that hepatocyte metabolism can also be successfully included in cytogenetic tests with short- and long-term cultures of mammalian target cells.

  17. The German ISS-Experiment Cellular Responses to Radiation in Space (CERASP): The Effects of Single and Combined Space Flight Conditions on Mammalian Cells

    NASA Astrophysics Data System (ADS)

    Baumstark-Khan, C.; Hellweg, C. E.; Arenz, A.

    The combined action of ionizing radiation and microgravity will continue to influence future space missions with special risks for astronauts on the Moon surface or for long duration missions to Mars Previous space flight experiments have reported additive neither sensitization nor protection as well as synergistic increased radiation effect under microgravity interactions of radiation and microgravity in different cell systems Although a direct effect of microgravity on enzymatic mechanisms can be excluded on thermo dynamical reasons modifications of cellular repair can not be excluded as such processes are under the control of cellular signal transduction systems which are controlled by environmental parameters presumably also by gravity DNA repair studies in space on bacteria yeast cells and human fibroblasts which were irradiated before flight gave contradictory results from inhibition of repair by microgravity to enhancement whereas others did not detect any influence of microgravity on repair At the Radiation Biology Department of the German Aerospace Center DLR recombinant bacterial and mammalian cell systems were developed as reporters for cellular signal transduction modulation by genotoxic environmental conditions The space experiment CERASP Cellular Responses to Radiation in Space to be performed at the International Space Station ISS will make use of such reporter cell lines thereby supplying basic information on the cellular response to radiation applied in microgravity One of the biological endpoints will be survival

  18. Ophiobolin A, a sesterterpenoid fungal phytotoxin, displays higher in vitro growth-inhibitory effects in mammalian than in plant cells and displays in vivo antitumor activity.

    PubMed

    Bury, Marina; Novo-Uzal, Esther; Andolfi, Anna; Cimini, Sara; Wauthoz, Nathalie; Heffeter, Petra; Lallemand, Benjamin; Avolio, Fabiana; Delporte, Cédric; Cimmino, Alessio; Dubois, Jacques; Van Antwerpen, Pierre; Zonno, Maria Chiara; Vurro, Maurizio; Poumay, Yves; Berger, Walter; Evidente, Antonio; De Gara, Laura; Kiss, Robert; Locato, Vittoria

    2013-08-01

    Ophiobolin A, a sesterterpenoid produced by plant pathogenic fungi, was purified from the culture extract of Drechslera gigantea and tested for its growth-inhibitory activity in both plant and mammalian cells. Ophiobolin A induced cell death in Nicotiana tabacum L. cv. Bright Yellow 2 (TBY-2) cells at concentrations ≥10 µM, with the TBY-2 cells showing typical features of apoptosis-like cell death. At a concentration of 5 µM, ophiobolin A did not affect plant cell viability but prevented cell proliferation. When tested on eight cancer cell lines, concentrations <1 µM of ophiobolin A inhibited growth by 50% after 3 days of culture irrespective of their multidrug resistance (MDR) phenotypes and their resistance levels to pro-apoptotic stimuli. It is, thus, unlikely that ophiobolin A exerts these in vitro growth-inhibitory effects in cancer cells by activating pro-apoptotic processes. Highly proliferative human keratinocytes appeared more sensitive to the growth-inhibitory effects of ophiobolin A than slowly proliferating ones. Ophiobolin A also displayed significant antitumor activity at the level of mouse survival when assayed at 10 mg/kg in the B16F10 mouse melanoma model with lung pseudometastases. Ophiobolin A could, thus, represent a novel scaffold to combat cancer types that display various levels of resistance to pro-apoptotic stimuli and/or various MDR phenotypes.

  19. Producing Newborn Synchronous Mammalian Cells

    NASA Technical Reports Server (NTRS)

    Gonda, Steve R.; Helmstetter, Charles E.; Thornton, Maureen

    2008-01-01

    A method and bioreactor for the continuous production of synchronous (same age) population of mammalian cells have been invented. The invention involves the attachment and growth of cells on an adhesive-coated porous membrane immersed in a perfused liquid culture medium in a microgravity analog bioreactor. When cells attach to the surface divide, newborn cells are released into the flowing culture medium. The released cells, consisting of a uniform population of synchronous cells are then collected from the effluent culture medium. This invention could be of interest to researchers investigating the effects of the geneotoxic effects of the space environment (microgravity, radiation, chemicals, gases) and to pharmaceutical and biotechnology companies involved in research on aging and cancer, and in new drug development and testing.

  20. Mammalian sperm morphometry.

    PubMed Central

    Gage, M J

    1998-01-01

    Understanding the adaptive significance of sperm form and function has been a challenge to biologists because sperm are highly specialized cells operating at a microscopic level in a complex environment. A fruitful course of investigation has been to use the comparative approach. This comparative study attempts to address some fundamental questions of the evolution of mammalian sperm morphometry. Data on sperm morphometry for 445 mammalian species were collated from published sources. I use contemporary phylogenetic analysis to control for the inherent non-independence of species and explore relationships between the morphometric dimensions of the three essential spermatozoal components: head, mid-piece and flagellum. Energy for flagellar action is metabolized by the mitochondrial-dense mid-piece and these combine to propel the sperm head, carrying the male haplotype, to the ovum. I therefore search for evolutionary associations between sperm morphometry and body mass, karyotype and the duration of oestrus. In contrast to previous findings, there is no inverse correlation between body weight and sperm length. Sperm mid-piece and flagellum lengths are positively associated with both head length and area, and the slopes of these relationships are discussed. Flagellum length is positively associated with mid-piece length but, in contrast to previous research and after phylogenetic control, I find no relationship between flagellum length and the volume of the mitochondrial sheath. Sperm head dimensions are not related to either genome mass or chromosome number, and there are no relationships between sperm morphometry and the duration of oestrus. PMID:9474794

  1. Hemoglobin redux: combining neutron and X-ray diffraction with mass spectrometry to analyse the quaternary state of oxidized hemoglobins.

    PubMed

    Mueser, Timothy C; Griffith, Wendell P; Kovalevsky, Andrey Y; Guo, Jingshu; Seaver, Sean; Langan, Paul; Hanson, B Leif

    2010-11-01

    Improvements in neutron diffraction instrumentation are affording the opportunity to re-examine the structures of vertebrate hemoglobins and to interrogate proton and solvent position changes between the different quaternary states of the protein. For hemoglobins of unknown primary sequence, structural studies of cyanomethemoglobin (CNmetHb) are being used to help to resolve sequence ambiguity in the mass spectra. These studies have also provided additional structural evidence for the involvement of oxidized hemoglobin in the process of erythrocyte senescence. X-ray crystal studies of Tibetan snow leopard CNmetHb have shown that this protein crystallizes in the B state, a structure with a more open dyad, which possibly has relevance to RBC band 3 protein binding and erythrocyte senescence. R-state equine CNmetHb crystal studies elaborate the solvent differences in the switch and hinge region compared with a human deoxyhemoglobin T-state neutron structure. Lastly, comparison of histidine protonation between the T and R state should enumerate the Bohr-effect protons.

  2. Hemoglobin redux: combining neutron and X-ray diffraction with mass spectrometry to analyse the quaternary state of oxidized hemoglobins

    SciTech Connect

    Mueser, Timothy C. Griffith, Wendell P.; Kovalevsky, Andrey Y.; Guo, Jingshu; Seaver, Sean; Langan, Paul; Hanson, B. Leif

    2010-11-01

    X-ray and neutron diffraction studies of cyanomethemoglobin are being used to evaluate the structural waters within the dimer–dimer interface involved in quaternary-state transitions. Improvements in neutron diffraction instrumentation are affording the opportunity to re-examine the structures of vertebrate hemoglobins and to interrogate proton and solvent position changes between the different quaternary states of the protein. For hemoglobins of unknown primary sequence, structural studies of cyanomethemoglobin (CNmetHb) are being used to help to resolve sequence ambiguity in the mass spectra. These studies have also provided additional structural evidence for the involvement of oxidized hemoglobin in the process of erythrocyte senescence. X-ray crystal studies of Tibetan snow leopard CNmetHb have shown that this protein crystallizes in the B state, a structure with a more open dyad, which possibly has relevance to RBC band 3 protein binding and erythrocyte senescence. R-state equine CNmetHb crystal studies elaborate the solvent differences in the switch and hinge region compared with a human deoxyhemoglobin T-state neutron structure. Lastly, comparison of histidine protonation between the T and R state should enumerate the Bohr-effect protons.

  3. Implementation of a Permeable Membrane Insert-based Infection System to Study the Effects of Secreted Bacterial Toxins on Mammalian Host Cells

    PubMed Central

    Flaherty, Rebecca A.; Lee, Shaun W.

    2016-01-01

    Many bacterial pathogens secrete potent toxins to aid in the destruction of host tissue, to initiate signaling changes in host cells or to manipulate immune system responses during the course of infection. Though methods have been developed to successfully purify and produce many of these important virulence factors, there are still many bacterial toxins whose unique structure or extensive post-translational modifications make them difficult to purify and study in in vitro systems. Furthermore, even when pure toxin can be obtained, there are many challenges associated with studying the specific effects of a toxin under relevant physiological conditions. Most in vitro cell culture models designed to assess the effects of secreted bacterial toxins on host cells involve incubating host cells with a one-time dose of toxin. Such methods poorly approximate what host cells actually experience during an infection, where toxin is continually produced by bacterial cells and allowed to accumulate gradually during the course of infection. This protocol describes the design of a permeable membrane insert-based bacterial infection system to study the effects of Streptolysin S, a potent toxin produced by Group A Streptococcus, on human epithelial keratinocytes. This system more closely mimics the natural physiological environment during an infection than methods where pure toxin or bacterial supernatants are directly applied to host cells. Importantly, this method also eliminates the bias of host responses that are due to direct contact between the bacteria and host cells. This system has been utilized to effectively assess the effects of Streptolysin S (SLS) on host membrane integrity, cellular viability, and cellular signaling responses. This technique can be readily applied to the study of other secreted virulence factors on a variety of mammalian host cell types to investigate the specific role of a secreted bacterial factor during the course of infection. PMID:27585035

  4. Effects of Tet-mediated Oxidation Products of 5-Methylcytosine on DNA Transcription in vitro and in Mammalian Cells

    NASA Astrophysics Data System (ADS)

    You, Changjun; Ji, Debin; Dai, Xiaoxia; Wang, Yinsheng

    2014-11-01

    5-methylcytosine (5-mC) is a well-characterized epigenetic regulator in mammals. Recent studies showed that Ten-eleven translocation (Tet) proteins can catalyze the stepwise oxidation of 5-mC to produce 5-hydroxymethylcytosine (5-HmC), 5-formylcytosine (5-FoC) and 5-carboxylcytosine (5-CaC). The exciting discovery of these novel cytosine modifications has stimulated substantial research interests about their roles in epigenetic regulation. Here we systematically examined the effects of the oxidized 5-mC derivatives on the efficiency and fidelity of DNA transcription using a recently developed competitive transcription and adduct bypass assay. Our results showed that, when located on the transcribed strand, 5-FoC and 5-CaC exhibited marginal mutagenic and modest inhibitory effects on DNA transcription mediated by single-subunit T7 RNA polymerase or multi-subunit human RNA polymerase II in vitro and in human cells. 5-HmC displayed relatively milder blocking effects on transcription, and no mutant transcript could be detectable for 5-HmC in vitro or in cells. The lack of considerable mutagenic effects of the oxidized 5-mC derivatives on transcription was in agreement with their functions in epigenetic regulation. The modest blocking effects on transcription suggested that 5-FoC and 5-CaC may function in transcriptional regulation. These findings provided new evidence for the potential functional interplay between cytosine methylation status and transcription.

  5. Effects of cerium oxide nanoparticles to fish and mammalian cell lines: An assessment of cytotoxicity and methodology.

    PubMed

    Rosenkranz, P; Fernández-Cruz, M L; Conde, E; Ramírez-Fernández, M B; Flores, J C; Fernández, M; Navas, J M

    2012-09-01

    Two cerium oxide nanoparticles (CeO(2) NPs) and one micro-sized CeO(2) particle were thoroughly characterized in their pristine form, in water and in cell culture medium. The particles were tested for cytotoxicity to the H4IIE rat hepatoma cell line or the RTG-2 rainbow trout gonadal cell line by means of four standard cytotoxicity assays. Nominal concentrations were verified by inductively coupled plasma mass spectrometry (ICP-MS) and methods were assessed for their suitability to detect reliably adverse effects due to particle exposure. All three particles showed aggregation in water and media. In the H4IIE cell line, the MTT cytotoxicity test revealed that negative effects could be observed for the CeO(2) NPs after 24h and for all particles after 72h of exposure, making the effects size, concentration and time dependent. No negative effect for the concentrations tested was detected for the remaining three assays and the RTG-2 cell line, making the MTT assay and the H4IIE cell line an appropriate system to assess adverse effects of CeO(2) NPs. A verification of the nominal concentration through ICP-MS revealed that there was a discrepancy between nominal and measured concentration depending on concentration and particle tested. Interferences of particles with assays were found to be present and need to be taken into consideration.

  6. The Apolar Channel in Cerebratulus lacteus Hemoglobin Is the Route for O2 Entry and Exit*

    PubMed Central

    Salter, Mallory D.; Nienhaus, Karin; Nienhaus, G. Ulrich; Dewilde, Sylvia; Moens, Luc; Pesce, Alessandra; Nardini, Marco; Bolognesi, Martino; Olson, John S.

    2008-01-01

    The major pathway for O2 binding to mammalian myoglobins (Mb) and hemoglobins (Hb) involves transient upward movement of the distal histidine (His-64(E7)), allowing ligand capture in the distal pocket. The mini-globin from Cerebratulus lacteus (CerHb) appears to have an alternative pathway between the E and H helices that is made accessible by loss of the N-terminal A helix. To test this pathway, we examined the effects of changing the size of the E7 gate and closing the end of the apolar channel in CerHb by site-directed mutagenesis. Increasing the size of Gln-44(E7) from Ala to Trp causes variation of association (k′O2) and dissociation (kO2) rate coefficients, but the changes are not systematic. More significantly, the fractions (Fgem ≈ 0.05–0.19) and rates (kgem ≈ 50–100 μs-1) of geminate CO recombination in the Gln-44(E7) mutants are all similar. In contrast, blocking the entrance to the apolar channel by increasing the size of Ala-55(E18) to Phe and Trp causes the following: 1) both k′O2 and kO2 to decrease roughly 4-fold; 2) Fgem for CO to increase from ∼0.05 to 0.45; and 3) kgem to decrease from ∼80 to ∼9 μs-1, as ligands become trapped in the channel. Crystal structures and low temperature Fourier-transform infrared spectra of Phe-55 and Trp-55 CerHb confirm that the aromatic side chains block the channel entrance, with little effect on the distal pocket. These results provide unambiguous experimental proof that diatomic ligands can enter and exit a globin through an interior channel in preference to the more direct E7 pathway. PMID:18840607

  7. UV action spectra for mammalian systems: their implications for the predicted effects of ozone depletion on skin cancer incidence

    SciTech Connect

    Setlow, R.B.

    1982-01-01

    The predicted environmental effect of UV-B depend on the action spectrum for the response studied. Since such spectra change rapidly - usually decreasing with increasing wavelength - and since the biological effects depend on the product of the action spectrum and the sun's spectrum at the surface of the earth which decreases with decreasing wavelength, a slight change in action spectrum will markedly influence the predicted effects of ozone depletion on biological systems. Thus, the key, but by no means only step in the prediction, is a knowledge of the action spectrum. Unfortunately, it is rare that we know or even hope to know the spectrum for biological systems of interest such as skin cancer induction, nor is it possible to do experiments with solar simulators on many systems. Hence, we must base our predictions on the photobiological properties of simple systems and the knowledge of their action spectra and general biological theories connecting simple cells with higher organisms.

  8. Hemoglobin D-Punjab: origin, distribution and laboratory diagnosis

    PubMed Central

    Torres, Lidiane de Souza; Okumura, Jéssika Viviani; Silva, Danilo Grünig Humberto da; Bonini-Domingos, Claudia Regina

    2015-01-01

    This review discusses hemoglobin D-Punjab, also known as hemoglobin D-Los Angeles, one of the most common hemoglobin variants worldwide. It is derived from a point mutation in the beta-globin gene (HBB: c.364G>C; rs33946267) prevalent in the Punjab region, Northwestern Indian. Hemoglobin D-Punjab can be inherited in heterozygosis with hemoglobin A causing no clinical or hematological alterations, or in homozygosis, the rarest form of inheritance, a condition that is commonly not related to clinical symptomatology. Moreover, this variant can exist in association with other hemoglobinopathies, such as thalassemias; the most noticeable clinical alterations occur when hemoglobin D-Punjab is associated to hemoglobin S. The clinical manifestations of this association can be similar to homozygosis for hemoglobin S. Although hemoglobin D-Punjab is a common variant globally with clinical importance especially in cases of double heterozygosis, hemoglobin S/D-Punjab is still understudied. In Brazil, for example, hemoglobin D-Punjab is the third most common hemoglobin variant. Thus, this paper summarizes information about the origin, geographic distribution, characterization and occurrence of hemoglobin D-Punjab haplotypes to try to improve our knowledge of this variant. Moreover, a list of the main techniques used in its identification is provided emphasizing the importance of complementary molecular analysis for accurate diagnosis. PMID:25818823

  9. Insensitivity of cerebral oxygen transport to oxygen affinity of hemoglobin-based oxygen carriers

    PubMed Central

    Koehler, Raymond C.; Fronticelli, Clara; Bucci, Enrico

    2008-01-01

    The cerebrovascular effects of exchange transfusion of various cell-free hemoglobins that possess different oxygen affinities are reviewed. Reducing hematocrit by transfusion of a non-oxygen-carrying solution dilates pial arterioles on the brain surface and increases cerebral blood flow to maintain a constant bulk oxygen transport to the brain. In contrast, transfusion of hemoglobins with P50 of 4–34 Torr causes constriction of pial arterioles that offsets the decrease in blood viscosity to maintain cerebral blood flow and oxygen transport. The autoregulatory constriction is dependent on synthesis of 20-HETE from arachidonic acid. This oxygen-dependent reaction is apparently enhanced by facilitated oxygen diffusion from the red cell to the endothelium arising from increased plasma oxygen solubility in the presence of low or high-affinity hemoglobin. Exchange transfusion of recombinant hemoglobin polymers with P50 of 3 and 18 Torr reduces infarct volume from experimental stroke. Cell-free hemoglobins do not require a P50 as high as red blood cell hemoglobin to facilitate oxygen delivery. PMID:18230370

  10. Effect-based assessment of persistent organic pollutant and pesticide dumpsite using mammalian CALUX reporter cell lines.

    PubMed

    Pieterse, B; Rijk, I J C; Simon, E; van Vugt-Lussenburg, B M A; Fokke, B F H; van der Wijk, M; Besselink, H; Weber, R; van der Burg, B

    2015-10-01

    A combined chemical and biological analysis of samples from a major obsolete pesticide and persistent organic pollutant (POP) dumpsite in Northern Tajikistan was carried out. The chemical analytical screening focused on a range of prioritized compounds and compounds known to be present locally. Since chemical analytics does not allow measurements of hazards in complex mixtures, we tested the use of a novel effect-based approach using a panel of quantitative high-throughput CALUX reporter assays measuring distinct biological effects relevant in hazard assessment. Assays were included for assessing effects related to estrogen, androgen, and progestin signaling, aryl hydrocarbon receptor-mediated signaling, AP1 signaling, genotoxicity, oxidative stress, chemical hypoxia, and ER stress. With this panel of assays, we first quantified the biological activities of the individual chemicals measured in chemical analytics. Next, we calculated the expected sum activity by these chemicals in the samples of the pesticide dump site and compared the results with the measured CALUX bioactivity of the total extracts of these samples. The results showed that particularly endocrine disruption-related effects were common among the samples. This was consistent with the toxicological profiles of the individual chemicals that dominated these samples. However, large discrepancies between chemical and biological analysis were found in a sample from a burn place present in this site, with biological activities that could not be explained by chemical analysis. This is likely to be caused by toxic combustion products or by spills of compounds that were not targeted in the chemical analysis.

  11. Antimutagenic, Antirecombinogenic, and Antitumor Effect of Amygdalin in a Yeast Cell-Based Test and Mammalian Cell Lines.

    PubMed

    Todorova, Atanaska; Pesheva, Margarita; Iliev, Ivan; Bardarov, Krum; Todorova, Teodora

    2017-02-01

    Amygdalin is a major component of the seeds of Rosaceae family of plants such as apricots, peaches, cherry, nectarines, apples, plums, and so on, as well as almonds. It is used in alternative medicine for cancer prevention, alleviation of fever, cough suppression, and quenching thirst. The aim of the present study is to determine the mutagenic and recombinogenic effects of amygdalin in a test system Saccharomyces cerevisiae and to evaluate its potential antitumor effect in a yeast cell-based test and colon cancer cell lines. Results obtained show that concentrations 25, 50, and 100 μg/mL did not have any cytotoxic, mutagenic, and carcinogenic effect in yeast cell-based tests. Pretreatment with amygdalin at concentration 100 μg/mL leads to around twofold of the cell survival and decrease of reverse mutation frequency, induced by the alkylating agent methyl methanesulfonate. The frequency of gene conversion and mitotic crossing-over is around threefold lower. The anticarcinogenic potential of amygdalin at the same concentration is presented as around fourfold reduction of Ty1 retrotransposition induced by hexavalent chromium. In summary, data presented in this study provide evidence concerning the inability of amygdalin itself to provoke events related to the initial steps of tumorigenesis. In addition, the observed antimutagenic/antirecombinogenic effect could be activation of error-free and error-prone recombination events. Based on the high selectivity toward normal or tumor cell lines, it could be speculated that amygdalin has higher cytotoxic effect in cell lines with higher proliferative and metabolic activity, which are the majority of fast developing tumors.

  12. Decreased damage from transient focal cerebral ischemia by transfusion of zero-link hemoglobin polymers in mouse

    PubMed Central

    Mito, Toshiaki; Nemoto, Masaaki; Kwansa, Herman; Sampei, Kenji; Habeeb, Murtuza; Murphy, Stephanie J.; Bucci, Enrico; Koehler, Raymond C.

    2008-01-01

    Background and Purpose Transfusion of large polymers of hemoglobin avoids the peripheral extravasation and hypertension associated with crosslinked tetrameric hemoglobin transfusion and may be more effective in rescuing brain from focal ischemia. Effects of transfusion of high-oxygen affinity, bovine hemoglobin polymers of different weight ranges were determined. Methods Hypervolemic exchange transfusion was performed during two hours of middle cerebral artery occlusion in mice. Results Compared to transfusion with a 5% albumin solution or no transfusion, infarct volume was reduced 40% by transfusion of a 6% solution containing hemoglobin polymers in the nominal range 500–14000 kDa. Infarct volume was not significantly reduced by transfusion of a lower concentration of 2–3% of this size range of polymers, 6% hemoglobin solutions without removal of polymers <500 kDa or >14000 kDa, or crosslinked hemoglobin tetramers with normal oxygen affinity. Exchange transfusion with the 6% solution of the 500–14000 kDa hemoglobin polymers did not improve the distribution of cerebral blood flow during focal ischemia and, in mice without ischemia, did not affect flow to brain or other major organs. Conclusion An intermediate size range of polymerized bovine hemoglobin possessing high oxygen affinity appears optimal for rescuing mouse brain from transient focal cerebral ischemia. A minimum concentration of a 6% solution is required, the rescue is superior to that obtained with crosslinked tetrameric hemoglobin possessing normal oxygen affinity, and tissue salvage is not associated with increased blood flow. This polymer solution avoids the adverse effects of severe renal and splanchnic vasoconstriction seen with crosslinked tetrameric hemoglobin. PMID:18988905

  13. Bradykinin-related peptides (BRPs) from skin secretions of three genera of phyllomedusine leaf frogs and their comparative pharmacological effects on mammalian smooth muscles.

    PubMed

    Jiang, Yingchun; Xi, Xinping; Ge, Lilin; Yang, Nan; Hou, Xiaojuan; Ma, Jie; Ma, Chengbang; Wu, Yuxin; Guo, Xiaoxiao; Li, Renjie; Zhou, Mei; Wang, Lei; Chen, Tianbao; Shaw, Chris

    2014-02-01

    While bradykinin has been identified in the skin secretions from several species of amphibian, bradykinin-related peptides (BRPs) are more common constituents. These peptides display a plethora of primary structural variations from the type peptide which include single or multiple amino acid substitutions, N- and/or C-terminal extensions and post-translational modifications such as proline hydroxylation and tyrosine sulfation. Such modified peptides have been reported in species from many families, including Bombinatoridae, Hylidae and Ranidae. The spectrum of these peptides in a given species is thought to be reflective of its predator profile from different vertebrate taxa. Here we report the isolation of BRPs and parallel molecular cloning of their respective biosynthetic precursor-encoding cDNAs from the skin secretions of the Mexican leaf frog (Pachymedusa dacnicolor), the Central American red-eyed leaf frog (Agalychnis callidryas) and the South American orange-legged leaf frog (Phyllomedusa hypochondrialis). Additionally, the eight different BRPs identified were chemically synthesized and screened for bioactivity using four different mammalian smooth muscle preparations and their effects and rank potencies were found to be radically different in these with some acting preferentially through bradykinin B1-type receptors and others through B(2)-type receptors.

  14. [Effects of phosphatidylinositol-3 kinase/protein kinase b/bone morphogenetic protein-15 pathway on the follicular development in the mammalian ovary].

    PubMed

    Wu, Yan-qing; Chen, Li-yun; Zhang, Zheng-hong; wang, Zheng-chao

    2013-04-01

    In mammals, ovarian follicle is made of an oocyte with its surrounding granulosa cells and theca cells. Follicular growth and development is a highly coordinated programmable process, which guarantees the normal oocyte maturation and makes it having the fertilizing capacity. The paracrine and autocrine between oocytes and granulosa cells are essential for the follicular development to provide a suitable microenvironment. Phosphatidylinositol-3 kinase /protein kinase B is one of these important regulatory signaling pathways during this developmental process, and bone morphogenetic protein-15 an oocyte-specific secreted signal molecule, which regulates the follicular development by paracrine in the mammalian ovary. The present article overviewed the role of phosphatidylinositol-3 kinase / protein kinase B signaling during the follicular development based on our previous investigation about protein kinase B /forkhead transcription factor forkhead family of transcription factors -3a, and then focused on the regulatory effects of bone morphogenetic protein-15, as a downstream signal molecule of phosphatidylinositol-3 kinase / forkhead family of transcription factors -3a pathway, on ovarian follicular development, which helped to further understand the molecular mechanism regulating the follicular development and to treat ovarian diseases like infertility.

  15. X-ray-induced chromosome damage in live mammalian cells, and improved measurements of its effects on their colony-forming ability.

    PubMed

    Joshi, G P; Nelson, W J; Revell, S H; Shaw, C A

    1982-02-01

    We have improved the precision of the technique described by Grote et al. (1981 a,b) for the observation of the radiation responses of live cultured mammalian cells with an incubated phase-contrast microscope: the colony-forming abilities of single cells obtained by selective detachment of mitoses (instead of cell pairs as previously) may now be followed individually and may be directly compared with chromosome damage detected after post-radiation mitosis (M1). An X-ray dose of 1.4 Gy to diploid Syrian hamster cells (BHK 21 C13) in G1 had no effect on cell ability to reach M1. If chromosome fragment loss was then detected (as micronuclei) in the daughter-cell pair then colony-forming ability nearly always deteriorated, and either a stop-growth (79 per cent) or a slow-growth (21 per cent) colony resulted; but chromosomal bridges which persisted beyond M1 broke during interphase 1 and themselves caused no detectable cell damage additional to that attributable to the micronuclei which accompanied them.

  16. Effects of a myosin-II inhibitor (N-benzyl-p-toluene sulphonamide, BTS) on contractile characteristics of intact fast-twitch mammalian muscle fibres.

    PubMed

    Pinniger, G J; Bruton, J D; Westerblad, H; Ranatunga, K W

    2005-01-01

    We have examined the effects of N-benzyl-p-toluene sulphonamide (BTS), a potent and specific inhibitor of fast muscle myosin-II, using small bundles of intact fibres or single fibres from rat foot muscle. BTS decreased tetanic tension reversibly in a concentration-dependent manner with half-maximal inhibition at approximately approximately 2 microM at 20 degrees C. The inhibition of tension with 10 microM BTS was marked at the three temperatures examined (10, 20 and 30 degrees C), but greatest at 10 degrees C. BTS decreased active muscle stiffness to a lesser extent than tetanic tension indicating that not all of the tension inhibition was due to a reduced number of attached cross-bridges. BTS-induced inhibition of active tension was not accompanied by any change in the free myoplasmic Ca2+ transients. The potency and specificity of BTS make it a very suitable myosin inhibitor for intact mammalian fast muscle and should be a useful tool for the examination of outstanding questions in muscle contraction.

  17. Grape skin phenolics as inhibitors of mammalian α-glucosidase and α-amylase--effect of food matrix and processing on efficacy.

    PubMed

    Lavelli, V; Sri Harsha, P S C; Ferranti, P; Scarafoni, A; Iametti, S

    2016-03-01

    Type-2 diabetes is continuously increasing worldwide. Hence, there is a need to develop functional foods that efficiently alleviate damage due to hyperglycaemia complications while meeting the criteria for a sustainable food processing technology. Inhibition of mammalian α-amylase and α-glucosidase was studied for white grape skin samples recovered from wineries and found to be higher than that of the drug acarbose. In white grape skins, quercetin and kaempferol derivatives, analysed by UPLC-DAD-MS, and the oligomeric series of catechin/epicatechin units and their gallic acid ester derivatives up to nonamers, analysed by MALDI-TOF-MS were identified. White grape skin was then used for enrichment of a tomato puree (3%) and a flat bread (10%). White grape skin phenolics were found in the extract obtained from the enriched foods, except for the higher mass proanthocyanidin oligomers, mainly due to their binding to the matrix and to a lesser extent to heat degradation. Proanthocyanidin solubility was lower in bread, most probably due to formation of binary proanthocyanin/protein complexes, than in tomato puree where possible formation of ternary proanthocyanidin/protein/pectin complexes can enhance solubility. Enzyme inhibition by the enriched foods was significantly higher than for unfortified foods. Hence, this in vitro approach provided a platform to study potential dietary agents to alleviate hyperglycaemia damage and suggested that grape skin phenolics could be effective even if the higher mass proanthocyanidins are bound to the food matrix.

  18. Influence of temperature and ontogeny on the levels of glucosinolates in broccoli (Brassica oleracea Var. italica) sprouts and their effect on the induction of mammalian phase 2 enzymes.

    PubMed

    Pereira, Fernanda Maria Valente; Rosa, Eduardo; Fahey, Jed W; Stephenson, Katherine K; Carvalho, Rosa; Aires, Alfredo

    2002-10-09

    Broccoli inflorescences have been recognized as components of healthy diets on the basis of their high content of fiber, vitamin C, carotenoids, and glucosinolates/isothiocyanates. Broccoli sprouts have been recently shown to have high levels of glucoraphanin (4-methylsulfinylbutyl glucosinolate), the precursor of the chemoprotective isothiocyanate, sulforaphane. This study evaluated the effects of temperature and developmental stage on the glucosinolate content of broccoli sprouts. Seedlings cultivated using a 30/15 degrees C (day/night) temperature regime had significantly higher glucosinolate levels (measured at six consecutive days postemergence) than did sprouts cultivated at lower temperatures (22/15 and 18/12 degrees C; p < 0.001). Both higher (33.1 degrees C) and lower (11.3 degrees C) constant temperatures induced higher glucosinolate levels in sprouts grown to a uniform size. Glucosinolate levels were highest in cotyledons and lowest in roots of sprouts dissected both early and late in the 11 day developmental span investigated. Nongerminated seeds have the highest glucosinolate levels and concordantly greater induction of mammalian phase 2 detoxication enzymes. Levels decline as sprouts germinate and develop, with consistently higher glucosinolate content in younger developmental stages, independent of the temperature regime. Temperature stress or its associated developmental anomalies induce higher glucosinolate levels, specific elevations in glucoraphanin content, and parallel induction of phase 2 chemoprotective enzymes.

  19. Maternal hemoglobin level and fetal outcome at low and high altitudes

    PubMed Central

    Steenland, Kyle; Tapia, Vilma

    2009-01-01

    Both, low (<7 g/dl) and high (>14.5 g/dl), maternal hemoglobin (Hb) levels have been related to poor fetal outcome. Most studies have been done at low altitude (LA). Here, we have sought to determine whether this relationship exists at both high and low altitude, and also whether there is an adverse effect of high altitude (HA) on fetal outcome independent of level of maternal hemoglobin. The study is based on a retrospective multicenter analysis of 35,449 pregnancies at LA and six other cities above 3000 meters. In analyses of all women at both LA and HA, those with Hb <9 g/dl had odds ratios (ORs) and 95% confidence intervals (CI) of 4.4 (CI: 2.8–6.7), 2.5 (CI: 1.9–3.2), and 1.4 (CI: 1.1–1.9) for stillbirths, preterm, and small for gestational age (SGA) births, respectively, compared with women with 11–12.9 g/dl of Hb, after adjustment for confounders. These risks by hemoglobin level differed little between women at LA and HA, suggesting that no correction of the definition of anemia is necessary for women at HA. Women living at high altitude with hemoglobin >15.5 g/dl had higher risks for stillbirths (OR: 1.3; CI: 1.05–1.3), preterm (OR: 1.5; CI 1.3–1.8), and SGA births (OR: 2.1, CI 1.8–2.3). There was also a significant adverse effect of living at HA, independent of hemoglobin level for all three outcomes (OR: 3.9, 1.7, and 2.3; CI: 2.8–5.2, 1.5–1.9, and 2.1–2.5) for stillbirths, preterms, and SGA respectively, after adjusting for hemoglobin level. Both, high and low maternal hemoglobin levels were related to poor pregnancy outcome, with similar effect of low hemoglobin in both LA and HA. Our data suggest, that maternal hemoglobin above 11 g/dl but below 13 g/dl is the area of minimal risk of poor adverse outcomes. Living at HA had an adverse effect independent of hemoglobin level. PMID:19741055

  20. Hemoglobin: A Nitric-Oxide Dioxygenase

    PubMed Central

    Gardner, Paul R.

    2012-01-01

    Members of the hemoglobin superfamily efficiently catalyze nitric-oxide dioxygenation, and when paired with native electron donors, function as NO dioxygenases (NODs). Indeed, the NOD function has emerged as a more common and ancient function than the well-known role in O2 transport-storage. Novel hemoglobins possessing a NOD function continue to be discovered in diverse life forms. Unique hemoglobin structures evolved, in part, for catalysis with different electron donors. The mechanism of NOD catalysis by representative single domain hemoglobins and multidomain flavohemoglobin occurs through a multistep mechanism involving O2 migration to the heme pocket, O2 binding-reduction, NO migration, radical-radical coupling, O-atom rearrangement, nitrate release, and heme iron re-reduction. Unraveling the physiological functions of multiple NODs with varying expression in organisms and the complexity of NO as both a poison and signaling molecule remain grand challenges for the NO field. NOD knockout organisms and cells expressing recombinant NODs are helping to advance our understanding of NO actions in microbial infection, plant senescence, cancer, mitochondrial function, iron metabolism, and tissue O2 homeostasis. NOD inhibitors are being pursued for therapeutic applications as antibiotics and antitumor agents. Transgenic NOD-expressing plants, fish, algae, and microbes are being developed for agriculture, aquaculture, and industry. PMID:24278729

  1. Comparative immunology of Galapagos iguana hemoglobins.

    PubMed

    Higgins, P J; Rand, C S

    1975-09-01

    The antigenic properties of the major hemoglobin component of the Galapgaos iguanas were studied using second-approximation qualitative and quantitative immunochemical techniques. Phylogenetic distances, relative to the Galapagos marine iguana. Amblyrhynchus cristatus, were established on the basis of immunological cross-reactions.

  2. Unrecognized hemoglobin SE disease as microcytosis

    PubMed Central

    Cooper, Barry; Guileyardo, Joseph; Mora, Adan

    2016-01-01

    Hemoglobin SE disease was first described during the 1950s as a relatively benign microcytosis, but increasing prevalence has revealed a predisposition towards vasoocclusive sickling. Recognition of SE hemoglobinopathies’ potential complications is crucial so medical measures can be utilized to avoid multiorgan injury. PMID:27365881

  3. RGB mapping of hemoglobin distribution in skin

    NASA Astrophysics Data System (ADS)

    Jakovels, Dainis; Spigulis, Janis; Rogule, Laura

    2011-07-01

    An experimental RGB imaging system based on commercial color camera was constructed, and its potential for mapping of hemoglobin distribution in skin was studied. Two types of LEDs (RGB and white "warm" LEDs) were compared as illuminators for acquiring images of vascular and pigmented skin malformations. A novel approach for studies of skin capillary refill by RGB analysis has been proposed and discussed.

  4. Hemoglobin-mediated nitric oxide signaling

    PubMed Central

    Helms, Christine; Kim-Shapiro, Daniel B.

    2013-01-01

    The rate that hemoglobin reacts with nitric oxide (NO) is limited by how fast NO can diffuse into the heme pocket. The reaction is as fast as any ligand/protein reaction can be and the result, when hemoglobin is in its oxygenated form, is formation of nitrate in what is known as the dioxygenation reaction. As nitrate, at the concentrations made through the dioxygenation reaction, is biologically inert, the only role hemoglobin was once thought to play in NO signaling was to inhibit it. However, there are now several mechanisms that have been discovered by which hemoglobin may preserve, control, and even create NO activity. These mechanisms involve compartmentalization of reacting species and conversion of NO from or into other species such as nitrosothiols or nitrite which could transport NO activity. Despite the tremendous amount of work devoted to this field, major questions concerning precise mechanisms of NO activity preservation as well as if and how Hb creates NO activity remain unanswered. PMID:23624304

  5. Metastable Polymerization of Sickle Hemoglobin in Droplets

    PubMed Central

    Aprelev, Alexey; Weng, Weijun; Zakharov, Mikhail; Rotter, Maria; Yosmanovich, Donna; Kwong, Suzanna; Briehl, Robin W.; Ferrone, Frank A.

    2007-01-01

    Sickle cell disease arises from a genetic mutation of one amino acid in each of the two hemoglobin β chains, leading to the polymerization of hemoglobin in the red cell upon deoxygenation, and is characterized by vascular crises and tissue damage due to the obstruction of small vessels by sickled cells. It has been an untested assumption that, in red cells that sickle, the growing polymer mass would consume monomers until the thermodynamically well-described monomer solubility was reached. By photolyzing droplets of sickle hemoglobin suspended in oil we find that polymerization does not exhaust the available store of monomers, but stops prematurely, leaving the solutions in a supersaturated, metastable state typically 20% above solubility at 37°C, though the particular values depend on the details of the experiment. We propose that polymer growth stops because the growing ends reach the droplet edge, whereas new polymer formation is thwarted by long nucleation times, since the hemoglobin concentration is lowered by depletion of monomers into the polymers that have formed. This finding suggests a new aspect to the pathophysiology of sickle cell disease, namely, that cells deoxygenated in the microcirculation are not merely undeformable, but will actively wedge themselves tightly against the walls of the microvasculature by a ratchet-like mechanism driven by the supersaturated solution. PMID:17493634

  6. Protecting effects specifically from low doses of ionizing radiation to mammalian cells challenge the concept of linearity

    SciTech Connect

    Feinendegen, L.E.; Bond, V.P.; Sondhaus, C.A.; Altman, K.I.

    1998-12-31

    This report examines the origin of tissue effects that may follow from different cellular responses to low-dose irradiation, using published data. Two principal categories of cellular responses are considered. One response category relates to the probability of radiation-induced DNA damage. The other category consists of low-dose induced changes in intracellular signaling that induce mechanisms of DNA damage control different from those operating at high levels of exposure. Modeled in this way, tissue is treated as a complex adaptive system. The interaction of the various cellular responses results in a net tissue dose-effect relation that is likely to deviate from linearity in the low-dose region. This suggests that the LNT hypothesis should be reexamined. The aim of this paper is to demonstrate that by use of microdosimetric concepts, the energy deposited in cell mass can be related to the occurrence of cellular responses, both damaging and defensive.

  7. Efficient cleavage of p220 by poliovirus 2Apro expression in mammalian cells: effects on vaccinia virus.

    PubMed

    Aldabe, R; Feduchi, E; Novoa, I; Carrasco, L

    1995-10-24

    Poliovirus protease 2A cleaves p220, a component of initiation factor eIF-4F. Polyclonal antibodies that recognize p220 and the cleaved products from different species have been raised. Transfection of several cell lines with poliovirus 2Apro cloned in different plasmids leads to efficient cleavage of p220 upon infection with VT7, a recombinant vaccinia virus that expresses the T7 RNA polymerase. Under these conditions vaccinia virus protein synthesis is severely inhibited, while expression of poliovirus protein 2C from a similar plasmid has no effect. These results show by the first time the effects of p220 cleavage on vaccinia virus translation in the infected cells.

  8. Quantitative techniques for assessing and controlling the dispersion and biological effects of multiwalled carbon nanotubes in mammalian tissue culture cells.

    PubMed

    Wang, Xiang; Xia, Tian; Ntim, Susana Addo; Ji, Zhaoxia; George, Saji; Meng, Huan; Zhang, Haiyuan; Castranova, Vincent; Mitra, Somenath; Nel, André E

    2010-12-28

    In vivo studies have demonstrated that the state of dispersion of carbon nanotubes (CNTs) plays an important role in generating adverse pulmonary effects. However, little has been done to develop reproducible and quantifiable dispersion techniques to conduct mechanistic studies in vitro. This study was to evaluate the dispersion of multiwalled carbon nanotubes (MWCNTs) in tissue culture media, with particular emphasis on understanding the forces that govern agglomeration and how to modify these forces. Quantitative techniques such as hydrophobicity index, suspension stability index, attachment efficiency, and dynamic light scattering were used to assess the effects of agglomeration and dispersion of as-prepared (AP), purified (PD), or carboxylated (COOH) MWCNTs on bronchial epithelial and fibroblast cell lines. We found that hydrophobicity is the major factor determining AP- and PD-MWCNT agglomeration in tissue culture media but that the ionic strength is the main factor determining COOH-MWCNT suspendability. Bovine serum albumin (BSA) was an effective dispersant for MWCNTs, providing steric and electrosteric hindrances that are capable of overcoming hydrophobic attachment and the electrostatic screening of double layer formation in ionic media. Thus, BSA was capable of stabilizing all tube versions. Dipalmitoylphosphatidylcholine (DPPC) provided additional stability for AP-MWCNTs in epithelial growth medium (BEGM). While the dispersion state did not affect cytotoxicity, improved dispersion of AP- and PD-MWCNTs increased TGF-β1 production in epithelial cells and fibroblast proliferation. In summary, we demonstrate how quantitative techniques can be used to assess the agglomeration state of MWCNTs when conducting mechanistic studies on the effects of dispersion on tissue culture cells.

  9. Low Concentration of Exogenous Carbon Monoxide Modulates Radiation-Induced Bystander Effect in Mammalian Cell Cluster Model.

    PubMed

    Wu, Wenqing; Nie, Lili; Yu, K N; Wu, Lijun; Kong, Peizhong; Bao, Lingzhi; Chen, Guodong; Yang, Haoran; Han, Wei

    2016-12-08

    During radiotherapy procedures, radiation-induced bystander effect (RIBE) can potentially lead to genetic hazards to normal tissues surrounding the targeted regions. Previous studies showed that RIBE intensities in cell cluster models were much higher than those in monolayer cultured cell models. On the other hand, low-concentration carbon monoxide (CO) was previously shown to exert biological functions via binding to the heme domain of proteins and then modulating various signaling pathways. In relation, our previous studies showed that exogenous CO generated by the CO releasing molecule, tricarbonyldichlororuthenium (CORM-2), at a relatively low concentration (20 µM), effectively attenuated the formation of RIBE-induced DNA double-strand breaks (DSB) and micronucleus (MN). In the present work, we further investigated the capability of a low concentration of exogenous CO (CORM-2) of attenuating or inhibiting RIBE in a mixed-cell cluster model. Our results showed that CO (CORM-2) with a low concentration of 30 µM could effectively suppress RIBE-induced DSB (p53 binding protein 1, p53BP1), MN formation and cell proliferation in bystander cells but not irradiated cells via modulating the inducible nitric oxide synthase (iNOS) andcyclooxygenase-2 (COX-2). The results can help mitigate RIBE-induced hazards during radiotherapy procedures.

  10. Effects of Caffeine on Radiation-Induced Phenomena Associated with Cell-Cycle Traverse of Mammalian Cells

    PubMed Central

    Walters, Ronald A.; Gurley, Lawrence R.; Tobey, Robert A.

    1974-01-01

    Caffeine induced a state of G1 arrest when added to an exponentially growing culture of Chinese hamster cells (line CHO). In addition to its effect on cell-cycle traverse, caffeine ameliorated a number of the responses of cells to ionizing radiation. The duration of the division delay period following X-irradiation of caffeine-treated cells was reduced, and the magnitude of reduction was dependent on caffeine concentration. Cells irradiated during the DNA synthetic phase in the presence of caffeine were delayed less in their exit from S, measured autoradiographically, and the radiation-induced reduction of radioactive thymidine incorporation into DNA was lessened. Cells synchronized by isoleucine deprivation, while being generally less sensitive to the effects of ionizing radiation than mitotically synchronized cells, were equally responsive to the effects of caffeine. The X-ray-induced reduction of phosphorylation of lysine-rich histone F1 was less in caffeine-treated cells than in untreated cells. Finally, survival after irradiation was only slightly reduced in caffeine-treated cells. A possible role of cyclic AMP in cell-cycle traverse of irradiated cells is discussed. PMID:4360269

  11. Radiation protection of in vitro mammalian cells: effects of hydroxyl radical scavengers on the slopes and shoulders of survival curves

    SciTech Connect

    Ewing, D.; Walton, H.L. )

    1991-05-01

    We have tested several chemical compounds, characterized and widely used as hydroxyl radical (.OH) scavengers, for their effects on the radiation sensitivity of Chinese hamster V79 cells irradiated in air or nitrogen. Our purpose is to reexamine the proposed relationship between the level of protection and the rates at which the scavengers react with .OH. We found that the additives can have two apparently independent effects on the shape of survival curves: a reduction in sensitivity (i.e., 'protection,' a decrease in the value of k) and an increase in the size of the shoulder of the survival curve (an increase in the value of Dq). We measured intracellular scavenger concentrations, and, using these values in our analysis, we found that neither of the two effects is correlated with the rates at which the scavengers react with .OH. Although these results could mean that .OH do not cause lethal damage, the interpretation we believe most probably correct is that these scavengers protect in multiple ways. The protection would occur in addition to or instead of simple .OH removal.

  12. Low Concentration of Exogenous Carbon Monoxide Modulates Radiation-Induced Bystander Effect in Mammalian Cell Cluster Model

    PubMed Central

    Wu, Wenqing; Nie, Lili; Yu, K. N.; Wu, Lijun; Kong, Peizhong; Bao, Lingzhi; Chen, Guodong; Yang, Haoran; Han, Wei

    2016-01-01

    During radiotherapy procedures, radiation-induced bystander effect (RIBE) can potentially lead to genetic hazards to normal tissues surrounding the targeted regions. Previous studies showed that RIBE intensities in cell cluster models were much higher than those in monolayer cultured cell models. On the other hand, low-concentration carbon monoxide (CO) was previously shown to exert biological functions via binding to the heme domain of proteins and then modulating various signaling pathways. In relation, our previous studies showed that exogenous CO generated by the CO releasing molecule, tricarbonyldichlororuthenium (CORM-2), at a relatively low concentration (20 µM), effectively attenuated the formation of RIBE-induced DNA double-strand breaks (DSB) and micronucleus (MN). In the present work, we further investigated the capability of a low concentration of exogenous CO (CORM-2) of attenuating or inhibiting RIBE in a mixed-cell cluster model. Our results showed that CO (CORM-2) with a low concentration of 30 µM could effectively suppress RIBE-induced DSB (p53 binding protein 1, p53BP1), MN formation and cell proliferation in bystander cells but not irradiated cells via modulating the inducible nitric oxide synthase (iNOS) andcyclooxygenase-2 (COX-2). The results can help mitigate RIBE-induced hazards during radiotherapy procedures. PMID:27941646

  13. Effect of Chromium Niacinate and Chromium Picolinate Supplementation on Lipid Peroxidation, TNF-α, IL-6, CRP, Glycated Hemoglobin, Triglycerides and Cholesterol Levels in blood of Streptozotocin-treated Diabetic Rats

    PubMed Central

    Jain, Sushil K.; Rains, Justin L.; Croad, Jennifer L.

    2013-01-01

    SUMMARY Chromium (Cr3+) supplementation facilitate normal protein, fat and carbohydrate metabolism, and is widely used by public in many countries. This study examined the effect of chromium niacinate (Cr-N) or chromium picolinate (Cr-P) supplementation on lipid peroxidation (LP), TNF-α, IL-6, CRP, glycosylated hemoglobin (HbA1), cholesterol and triglycerides (TG) in diabetic rats. Diabetes (D) was induced in Sprague Dawley rats by streptozotocin (STZ) (ip, 65 mg/kg BW). Control buffer, Cr-N or Cr-P (400 µg Cr/Kg BW) was administered by gavages daily for 7 wks. Blood was collected by heart puncture using light anesthesia. Diabetes caused a significant increase in blood levels of TNF-α, IL-6, glucose, HbA1, cholesterol, TG and LP. Compared with D, Cr-N supplementation lowered the blood levels of TNF-α (p=0.04), IL-6 (p=0.02), CRP (p=0.02) LP (p=0.01), HbA1 (p=0.02), TG (p=0.04) and cholesterol (p=0.04). Compared with D, Cr-P supplementation showed a decrease in TNF-α (p=0.02), IL-6 (p=0.02) and LP (p=0.01). Chromium niacinate lowers blood levels of pro-inflammatory cytokines (TNF-α, IL-6, CRP), oxidative stress and lipids levels in diabetic rats, and appears to be more effective form of Cr3+-supplementation. This study suggests that Cr3+-supplementation can lower risk of vascular inflammation in diabetes. PMID:17854708

  14. Effect of chromium niacinate and chromium picolinate supplementation on lipid peroxidation, TNF-alpha, IL-6, CRP, glycated hemoglobin, triglycerides, and cholesterol levels in blood of streptozotocin-treated diabetic rats.

    PubMed

    Jain, Sushil K; Rains, Justin L; Croad, Jennifer L

    2007-10-15

    Chromium (Cr(3+)) supplementation facilitates normal protein, fat, and carbohydrate metabolism, and is widely used by the public in many countries. This study examined the effect of chromium niacinate (Cr-N) or chromium picolinate (Cr-P) supplementation on lipid peroxidation (LP), TNF-alpha, IL-6, C-reactive protein (CRP), glycosylated hemoglobin (HbA(1)), cholesterol, and triglycerides (TG) in diabetic rats. Diabetes (D) was induced in Sprague-Dawley rats by streptozotocin (STZ) (ip, 65 mg/kg BW). Control buffer, Cr-N, or Cr-P (400 microg Cr/kg BW) was administered by gavages daily for 7 weeks. Blood was collected by heart puncture using light anesthesia. Diabetes caused a significant increase in blood levels of TNF-alpha, IL-6, glucose, HbA(1), cholesterol, TG, and LP. Compared with D, Cr-N supplementation lowered the blood levels of TNF-alpha (P=0.04), IL-6 (P=0.02), CRP (P=0.02), LP (P=0.01), HbA(1) (P=0.02), TG (P=0.04), and cholesterol (P=0.04). Compared with D, Cr-P supplementation showed a decrease in TNF-alpha (P=0.02), IL-6 (P=0.02), and LP (P=0.01). Chromium niacinate lowers blood levels of proinflammatory cytokines (TNF-alpha, IL-6, CRP), oxidative stress, and lipids levels in diabetic rats, and appears to be a more effective form of Cr(3+) supplementation. This study suggests that Cr(3+) supplementation can lower the risk of vascular inflammation in diabetes.

  15. The mammalian blastocyst.

    PubMed

    Frankenberg, Stephen R; de Barros, Flavia R O; Rossant, Janet; Renfree, Marilyn B

    2016-01-01

    The blastocyst is a mammalian invention that carries the embryo from cleavage to gastrulation. For such a simple structure, it exhibits remarkable diversity in its mode of formation, morphology, longevity, and intimacy with the uterine endometrium. This review explores this diversity in the light of the evolution of viviparity, comparing the three main groups of mammals: monotremes, marsupials, and eutherians. The principal drivers in blastocyst evolution were loss of yolk coupled with evolution of the placenta. An important outcome of blastocyst development is differentiation of two extraembryonic lineages (trophoblast and hypoblast) that contribute to the placenta. While in many species trophoblast segregation is often coupled with blastocyst formation, in marsupials and at least some Afrotherians, these events do not coincide. Thus, many questions regarding the conservation of molecular mechanisms controlling these events are of great interest but currently unresolved. For further resources related to this article, please visit the WIREs website.

  16. Effects on in Vivo and in Vitro Exposure to Excess Gravity on Growth and Differentiation of Mammalian Embryos

    NASA Technical Reports Server (NTRS)

    Duke, J.

    1985-01-01

    Studies on the development of embryonic mouse tissues exposed to excess gravity in vitro and in vivo are discussed. Suppression is seen in limb buds cultured under 3G. Mouse palates were exposed to excess G in vitro, 13- and 14-day palates were exposed to 2.6G for 24 hours. For in vivo studies, a small animal centrifuge was constructed. When the centrifuge is operated at 40 and 45 rpm, the linear accelerations generated range from 1.8 to 3.5G. The effects of gravity on body weights and on reproduction is also presented.

  17. Hemoglobin Hasharon (α247 his(CD5)β2): a hemoglobin found in low concentration

    PubMed Central

    Charache, S.; Mondzac, A. M.; Gessner, U.

    1969-01-01

    Hemoglobin Hasharon (α247 his(CD5)β2) was found to comprise only 16-19% of hemolysates of carriers. These heterozygotes appeared to have mild, compensated, hemolytic anemia. Hb Hasharon was more heat-labile than hemoglobins A, S, or C. Its specific activity was higher than that of Hb A after administration of 59Fe to two carriers. When hemoglobin synthesis by bone marrow cells was studied in vitro, about 18% of incorporated leucine appeared in the Hb Hasharon fraction. It is suggested that Hb Hasharon is unstable in vivo, and that mild hemolytic anemia and a relatively small decrease in its concentration in hemolysates result from its denaturation within red cells. Decreased synthesis, which appears to be the major cause of the small amount of abnormal hemoglobin, may protect heterozygotes from clinically significant hemolytic anemia. Images PMID:5780195

  18. Protection of mammalian cells by o-phenanthroline from lethal and DNA-damaging effects produced by active oxygen species.

    PubMed

    de Mello Filho, A C; Meneghini, R

    1985-10-30

    Active oxygen species are suspected as being a cause of the cellular damage that occurs at the site of inflammation. Phagocytic cells accumulate at these sites and produce superoxide ion, hydrogen peroxide and hydroxyl radical. The ultimate killing species, the cellular target and the mechanism whereby the lethal injury is produced are unknown. We exposed mouse fibroblasts to xanthine oxidase and acetaldehyde, a system which mimics the membrane of phagocytic cells in terms of production of oxygen species. We observed that the generation of these species produced DNA strand breaks and cellular death. The metal chelator o-phenanthroline completely abolished the former effect, and at the same time it effectively protected the cells from lethal injuries. Because complexing iron o-phenanthroline prevents the formation of hydroxyl radical by the Fendon reaction (Fe(II) + H2O2----Fe(III) + OH- + OH.), it is proposed that most of the cell death and DNA damage are brought about by OH radical, produced from other species by iron-mediated reactions.

  19. The uncoupling effect of diacylglycerol on gap junctional communication of mammalian heart cells is independent of protein kinase C.

    PubMed

    Bastide, B; Hervé, J C; Délèze, J

    1994-10-01

    Possible regulatory effects on cell-to-cell communication of a synthetic diacylglycerol, an activator of protein kinase C (PKC), were examined in pairs of synchronously beating ventricular myocytes of neonatal rats in primary culture. Junctional communication was estimated by measuring either the rate constant of dye diffusion, with the fluorescence recovery after photobleaching technique, or the cell-to-cell electrical conductance with a double whole-cell voltage clamp. The addition of a freshly prepared emulsion of 1-oleoyl-2-acetyl-sn-glycerol (OAG, 100 micrograms/ml), either in the bath or in the solution filling the patch pipet, was seen to interrupt intercellular communication within approximately 8 to 10 min. This effect is neither mimicked by stimulation of PKC by a phorbol ester, nor prevented by PKC inhibitors, making it unlikely that, in these cells, PKC activation could induce intercellular uncoupling. During OAG exposures, the intracellular calcium concentration was very modestly increased (by a factor 1.5 to 2), which does not suffice to account for uncoupling. OAG might trigger interruption of cell-to-cell communication by a mechanism analogous to that of other lipophilic molecules (such as aliphatic alcohols or long chain unsaturated fatty acids) which interfere with gap junctions.

  20. Peroxisome proliferator-activated receptor-γ agonist inhibits the mammalian target of rapamycin signaling pathway and has a protective effect in a rat model of status epilepticus

    PubMed Central

    SAN, YONG-ZHI; LIU, YU; ZHANG, YU; SHI, PING-PING; ZHU, YU-LAN

    2015-01-01

    Peroxisome proliferator-activated receptor γ (PPAR-γ) has a protective role in several neurological diseases. The present study investigated the effect of the PPAR-γ agonist, pioglitazone, on the mammalian target of rapamycin (mTOR) signaling pathway in a rat model of pentylenetetrazol (PTZ)-induced status epilepticus (SE). The investigation proceeded in two stages. First, the course of activation of the mTOR signaling pathway in PTZ-induced SE was examined to determine the time-point of peak activity, as reflected by phopshorylated (p)-mTOR/mTOR and p-S6/S6 ratios. Subsequently, pioglitazone was administrated intragastrically to investigate its effect on the mTOR signaling pathway, through western blot and immunochemical analyses. The levels of the interleukin (IL)-1β and IL-6 inflammatory cytokines were detected using ELISA, and neuronal loss was observed via Nissl staining. In the first stage of experimentation, the mTOR signaling pathway was activated, and the p-mTOR/mTOR and p-S6/S6 ratios peaked on the third day. Compared with the vehicle treated-SE group, pretreatment with pioglitazone was associated with the loss of fewer neurons, lower levels of IL-1β and IL-6, and inhibition of the activation of the mTOR signaling pathway. Therefore, the mTOR signaling pathway was activated in the PTZ-induced SE rat model, and the PPAR-γ agonist, pioglitazone, had a neuroprotective effect, by inhibiting activation of the mTOR pathway and preventing the increase in the levels of IL-1β and IL-6. PMID:25891824

  1. Construction of simple and efficient siRNA validation systems for screening and identification of effective RNAi-targeted sequences from mammalian genes.

    PubMed

    Tsai, Wen-Hui; Chang, Wen-Tsan

    2014-01-01

    RNA interference (RNAi) is an evolutionarily conserved mechanism of gene silencing induced by double-stranded RNAs (dsRNAs). Among the widely used dsRNAs, small interfering RNAs (siRNAs) and short hairpin RNAs have evolved as extremely powerful and the most popular gene silencing reagents. The key challenge to achieving efficient gene silencing especially for the purpose of therapeutics is mainly dependent on the effectiveness and specificity of the selected RNAi-targeted sequences. Practically, only a small number of dsRNAs are capable of inducing highly effective and sequence-specific gene silencing via RNAi mechanism. In addition, the efficiency of gene silencing induced by dsRNAs can only be experimentally examined based on inhibition of the target gene expression. Therefore, it is essential to develop a fully robust and comparative validation system for measuring the efficacy of designed dsRNAs. In this chapter, we focus our discussion on a reliable and quantitative reporter-based siRNA validation system that has been previously established in our laboratory. The system consists of a short synthetic DNA fragment containing an RNAi-targeted sequence of interest and two expression vectors for targeting reporter and triggering siRNA expressions. The efficiency of siRNAs is determined by their abilities to inhibit expression of the targeting reporters with easily quantified readouts including enhanced green fluorescence protein and firefly luciferase. Since only a readily available short synthetic DNA fragment is needed for constructing this reliable and efficient reporter-based siRNA validation system, this system not only provides a powerful strategy for screening highly effective RNAi-targeted sequences from mammalian genes but also implicates the use of RNAi-based dsRNA reagents for reverse functional genomics and molecular therapeutics.

  2. pH-dependent effects of the ionophore nigericin on response of mammalian cells to radiation and heat treatment.

    PubMed

    Varnes, M E; Glazier, K G; Gray, C

    1989-02-01

    The extracellular pH (pHe) in many solid tumors is often lower than the pH of normal tissues. The K+/H+ ionophore nigericin is toxic to CHO cells when pHe is below but not above 6.5, and thus it has potential for selective killing of tumor cells in an acidic environment. This study examines the pH-dependent effects of nigericin on the response of CHO cells to radiation and heat treatment. Cells held for 4 h in Hank's balanced salt solution, after 9 Gy irradiation, exhibit potentially lethal damage recovery (PLDR) which is maximal at pHe 6.7-6.8. Addition of nigericin, postirradiation, not only inhibits PLDR when pHe is below 6.8, but interacts synergistically with radiation to reduce survival below that of cells plated immediately after irradiation when pHe is 6.4 or lower. Nigericin enhances heat killing of CHO cells perferentially under acidic conditions, and where neither heat nor drug treatment alone is significantly toxic. Survival of cells held for 30 min at 42.1 degrees C in the presence of 1.0 microgram/ml nigericin is 0.6, 0.08, 0.003, and 0.00003 at pHe 7.4, 6.8, 6.6, and 6.4, respectively, relative to survival of 1.0 in untreated cultures. The biochemical effects of nigericin at pHe 7.4 vs pHe 6.4 have been investigated. Nigericin inhibits respiration, stimulates glucose consumption, and causes dramatic changes in intracellular concentrations of Na+ and K+ at pHe 7.4 as well as 6.4. The drug reduces intracellular levels of ATP, GTP, and ADP but has more pronounced effects under acidic incubation conditions. Others have shown that nigericin equilibrates pHe and intracellular pH (pHi) only when pHe is 6.5 or lower. Our observations and those of others have led us to conclude that lowering of pHi by nigericin is either the direct or indirect cause of enhancement of radiation and heat killing of cells in an acidic environment.

  3. Determination of the Chronic Mammalian Toxicological Effects of TNT (twenty-Four Month Chronic Toxicity/Carcinogenicity Study of Trinitrotoluene (TNT) in the Fischer 344 Rat). Volume 1

    DTIC Science & Technology

    1984-12-01

    examinations and histologic evaluation, however, failed to detect treatment-related ocular abnormalities. Anemia consisting of reduced hematocrit, hemoglobin...subjected to comprehensive histopathologic examination, defined as microscopic examination of the following tissues and/or organs: Adrenals * Brain (3...at least the following tissues and/or organs: Brain (section of frontal cortex and basal ganglia; section of parietal cortex and thalmus and section

  4. Effects of solar ultraviolet photons on mammalian cell DNA. [UVA (320-400 nm):a2

    SciTech Connect

    Peak, M.J.; Peak, J.G.

    1991-01-01

    This document presents information on the possible mechanisms of carcinogenesis caused by UVA (ultraviolet radiation in the 320--400 nm region). Most studies showing the carcinogenic effects of ultraviolet light have concentrated on UVB (280--320 nm). UVA had been considered harmless even though it penetrates biological tissues better than UVB. Recently, it has become apparent that UVA is also capable of causing damage to cellular DNA. This was unexpected because the DNA UV absorption spectrum indicates a negligible probability that photons of wavelengths longer than 320 nm will be directly absorbed. The most common defects induced in DNA by UVB are pyrimidine photoproducts, such as thymidine dimers. UVA photons produce defects resembling those caused by ionizing radiations: single- and double-strand breaks, and DNA-protein crosslinks. This paper also discusses the role of DNA repair mechanisms in UVA-induced defects and the molecular mechanisms of UVA damage induction. 38 refs. (MHB)

  5. Elucidating the mode of action of urea on mammalian serum albumins and protective effect of sodium dodecyl sulfate.

    PubMed

    Khan, Javed Masood; Chaturvedi, Sumit Kumar; Khan, Rizwan Hasan

    2013-11-22

    The effect of sodium dodecyl sulfate (SDS) on human, bovine, porcine, rabbit and sheep serum albumins were investigated at pH 3.5 by using various spectroscopic techniques like circular dichroism (CD), intrinsic fluorescence and dynamic light scattering (DLS). In the presence of 4.0mM SDS the secondary structure of all the albumins were not affected as measured by CD but fluorescence spectra revealed 8.0 nm blue shift in emission maxima. We further checked the stability of albumins in the absence and presence of 4.0mM SDS by urea and temperature at pH 3.5. In the absence of SDS, urea starts unfolding both secondary as well as tertiary structural elements of the all the albumins at approximately 2.0M urea but in the presence of 4.0mM SDS, urea was unable to unfold even up to 9.0M. The albumins were thermally less stable at pH 3.5 with decrease in Tm but in the presence of 4.0mM SDS, the Tm was increased. From this study, it was concluded that SDS is showing a protective effect against urea as well as thermal denaturation of albumins. This behavior may be due to electrostatic as well as the hydrophobic interaction of SDS with albumins. Further, we have proposed the mechanism of action of urea. It was found that urea interacted with proteins directly when proteins are in charged form. Indirect interaction may be taking place when the environment is more hydrophobic.

  6. An electrophysiological analysis of the effects of noradrenaline and alpha-receptor antagonists on neuromuscular transmission in mammalian muscular arteries.

    PubMed

    Holman, M E; Surprenant, A

    1980-01-01

    1 The effects of exogenously applied noradrenaline (NA) and alpha-adrenoceptor antagonists on the mechanical and intracellularly recorded responses to perivascular nerve stimulation were examined in the rabbit ear artery, rabbit saphenous artery and rat tail artery. 2 Excitatory junction potentials (e.j.ps) and action potentials recorded from these smooth muscles were not blocked or depressed by phentolamine, phenoxybenzamine, prazosin, or labetolol in concentrations as high as 10 microgram/ml. Phentolamine (1 to 10 microgram/ml) depressed neurally-evoked contractions of the ear and saphenous, but not the tail artery, and also depressed the contractions produced by direct muscle stimulation in the ear and saphenous arteries. Prazosin and labetolol (0.1 to 10 microgram/ml) had no effect on the neurally evoked contractile response in any of the arteries examined. 3 The amplitude of the steady-state e.j.p. during repetitive stimulation at 0.45 to 2 Hz was increased by phentolamine or phenoxybenzamine but not by prazosin or labetolol. Phentolamine and phenoxybenzamine also increased the amplitude of the e.j.p. evoked by a single stimulus in the majority of the preparations. 4 Concentrations of NA greater than or equal to 1 microgram/ml depolarized the smooth muscle while concentrations greater than or equal to 0.5 microgram/ml depressed the amplitude of the e.j.ps recorded from these arteries. alpha-Antagonists did not suppress either the NA-induced membrane depolarization or depression of e.j.ps. 5 These observations call into question the physiological relevance of both pre- and postsynaptic alpha-receptors in regard to adrenergic neuromuscular transmission in muscular arteries.

  7. Asymmetric hemoglobins, their thiol content, and blood glutathione of the scalloped hammerhead shark, Sphyrna lewini.

    PubMed

    Dafré, A L; Reischl, E

    1997-03-01

    Starch gel electrophoresis pH 8.6, or PAGE pH 8.9, of the scalloped hammerhead shark hemolysates showed three hemoglobins (Hb). An additional Hb between the two most mobile electrophoretic components was seen in starch gel electrophoresis, pH 8.1, and also in highly loaded PAGE gels. The relative concentration of these Hbs was variable among individuals, when accessed at pH 8.1. Dilution of hemolysates led to a redistribution of the Hb tetramer subunits. Under denaturing conditions, the unfractionated hemolysate was resolved in 3 Hb subunits. Isolated Hbs, named SL I-SL IV, showed unusual subunit compositions: SL I, the least mobile, is "b3c"; SL II is "a2bc"; SL III and SL IV are composed only by "a" subunits. Hemoglobins in the whole hemolysate have an average of two reactive cysteines per tetramer, which were not easily S-thiolated by glutathione, as is the case for related species. After hemoglobin denaturation, six additional -SH groups were titrated by Ellman's reagent. Methemoglobin content was low in the erythrocytes of nine examined specimens, 1.13 +/- 1.90%. High values for total erythrocyte glutathione (GSH) were found: 4.5 +/- 0.7 mM; n = 7. The ratio of 1.4 +/- 0.4 GSH/Hb is higher than usually reported for mammalians.

  8. Effects of quinine and apamin on the calcium-dependent potassium permeability of mammalian hepatocytes and red cells.

    PubMed Central

    Burgess, G M; Claret, M; Jenkinson, D H

    1981-01-01

    1. K-sensitive electrodes placed in the extracellular fluid have been used to show that ATP and noradrenaline cause a rapid loss of up to 10% of the K content of isolated guinea-pig hepatocytes. 2. The hypothesis tha this response is a consequence of a rise in the K permeability of the hepatocyte membrane triggered by an increase in cytosolic Ca is supported by the finding that the divalent cation ionophore A23187 also initiated K loss, in this instance of up to 20-25% of the amount in the cells. 3. Under similar conditions A23187 caused a transient increase, followed by a larger decrease, in the 45Ca content of guinea-pig hepatocytes equilibrated with this isotope. The decrease alone was seen with ATP and noradrenaline. 4. Quinine (1 mM) and the bee venom neurotoxin apamin (10 nM) greatly reduced the effect of ATP, noradrenaline and A23187 on K content without affecting the changes in 45Ca movement. 5. Apamin (10 nM) also abolished the increase in 42K efflux which follows the application of the alpha-adrenoceptor agonist amidephrine to rabbit liver slices; the concurrent rises in 45Ca efflux and glucose release were unaffected. 6. It was concluded that quinine and apamin are able to block either the Ca-dependent K channels present in guinea-pig and rabbit liver cell membranes or the mechanism that controls them. 7. Surprisingly, rat hepatocytes took up rather than lost K when treated with the concentrations of ATP, noradrenaline or A23187 that initiated K loss from guinea-pig cells. This response was greatly reduced by ouabain. 8. Application of large concentrations of A23187 to rat hepatocytes caused K loss associated with cell death. 9. The influence of apamin (10-1000 nM) and quinine (200-1000 micro M) on the Ca-dependent K permeability of red blood cells and ghosts was also studied. Apamin was without effect even when applied to both sides of the ghost membrane, whereas quinine caused inhibition, as reported by others. 10. The results suggest that Ca

  9. 21 CFR 864.7455 - Fetal hemoglobin assay.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Fetal hemoglobin assay. 864.7455 Section 864.7455 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... hemoglobin polypeptide chains). The hemoglobin determination may be made by methods such as...

  10. 21 CFR 864.7455 - Fetal hemoglobin assay.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Fetal hemoglobin assay. 864.7455 Section 864.7455 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... hemoglobin polypeptide chains). The hemoglobin determination may be made by methods such as...

  11. 21 CFR 864.7455 - Fetal hemoglobin assay.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Fetal hemoglobin assay. 864.7455 Section 864.7455 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... hemoglobin polypeptide chains). The hemoglobin determination may be made by methods such as...

  12. 21 CFR 864.7455 - Fetal hemoglobin assay.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fetal hemoglobin assay. 864.7455 Section 864.7455 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... hemoglobin polypeptide chains). The hemoglobin determination may be made by methods such as...

  13. Sensitivity of Routine Tests for Urine Protein to Hemoglobin

    PubMed Central

    Jansen, Barbara S.; Lumsden, John H.

    1985-01-01

    Increasing concentrations of canine hemoglobin were added to aliquots of urine and saline to determine the relative sensitivity of several hemoglobin and protein detection methods including commercial reagent strips and sulfosalicylic acid. The hemoglobin detection pads of the reagent strips were 50 times more sensitive than the protein detection pads, indicating the presence of hemoglobin at a concentration of 0.001 g/L whereas the protein pads did not react positively unless the hemoglobin concentration exceeded 0.05 g/L. The sulfosalicylic acid test was the least sensitive, detecting hemoglobin only at concentrations of 0.4 g/L or higher. These results were similar for hemoglobin added either in the form of lysed red blood cells, intact red blood cells or associated with plasma proteins in whole blood. It was shown that a urine hemoglobin concentration eliciting less than the maximal score on the hemoglobin detection pad will not be detected as “protein” either with the commercial urinalysis strips or with sulfosalicylic acid. It was also seen that hemoglobin becomes visible as a red pigment when exceeding 0.3-0.5 g/L in a clear, light urine. It follows that a positive urine protein reading in the presence of a positive but less than maximal hemoglobin score or a protein reading exceeding 1.0 g/L in a nonpigmented urine indicates “true” proteinuria in excess of hemoglobin and plasma proteins associated with urinary tract hemorrhage. PMID:17422554

  14. Photopyroelectric Technique for Hemoglobin Assessment in Human Blood

    NASA Astrophysics Data System (ADS)

    Balderas-López, J. A.; Gómez y Gómez, Y. M.; Bautista-Ramírez, M. E.

    2015-06-01

    A new photopyroelectric (PPE) methodology, for optical characterization of general liquids, was used for the assessment of hemoglobin in human blood. The optical absorption coefficient of a hemoglobin reference was measured with this PPE methodology and its corresponding absorptivity, at 532 nm, was obtained. This last reference was used for hemoglobin quantification of blood from a healthy man.

  15. 21 CFR 522.1125 - Hemoglobin glutamer-200 (bovine).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Hemoglobin glutamer-200 (bovine). 522.1125 Section... § 522.1125 Hemoglobin glutamer-200 (bovine). (a) Specifications. Each 125 milliliter bag contains 13 grams per deciliter of polymerized hemoglobin of bovine origin in modified Lactated Ringer's...

  16. 21 CFR 522.1125 - Hemoglobin glutamer-200 (bovine).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Hemoglobin glutamer-200 (bovine). 522.1125 Section... § 522.1125 Hemoglobin glutamer-200 (bovine). (a) Specifications. Each 125 milliliter bag contains 13 grams per deciliter of polymerized hemoglobin of bovine origin in modified Lactated Ringer's...

  17. 21 CFR 522.1125 - Hemoglobin glutamer-200 (bovine).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Hemoglobin glutamer-200 (bovine). 522.1125 Section... § 522.1125 Hemoglobin glutamer-200 (bovine). (a) Specifications. Each 125 milliliter bag contains 13 grams per deciliter of polymerized hemoglobin of bovine origin in modified Lactated Ringer's...

  18. 21 CFR 864.7455 - Fetal hemoglobin assay.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Fetal hemoglobin assay. 864.7455 Section 864.7455...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7455 Fetal hemoglobin assay. (a) Identification. A fetal hemoglobin assay is a device that is used to determine the...

  19. 21 CFR 522.1125 - Hemoglobin glutamer-200 (bovine).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Hemoglobin glutamer-200 (bovine). 522.1125 Section... § 522.1125 Hemoglobin glutamer-200 (bovine). (a) Specifications. Each 125 milliliter bag contains 13 grams per deciliter of polymerized hemoglobin of bovine origin in modified Lactated Ringer's...

  20. Biological Effects of Particles with Very High Energy Deposition on Mammalian Cells Utilizing the Brookhaven Tandem Van de Graaff Accelerator

    NASA Technical Reports Server (NTRS)

    Saha, Janapriya; Cucinotta, Francis A.; Wang, Minli

    2013-01-01

    High LET radiation from GCR (Galactic Cosmic Rays) consisting mainly of high charge and energy (HZE) nuclei and secondary protons and neutrons, and secondaries from protons in SPE (Solar Particle Event) pose a major health risk to astronauts due to induction of DNA damage and oxidative stress. Experiments with high energy particles mimicking the space environment for estimation of radiation risk are being performed at NASA Space Radiation Laboratory at BNL. Experiments with low energy particles comparing to high energy particles of similar LET are of interest for investigation of the role of track structure on biological effects. For this purpose, we report results utilizing the Tandem Van de Graaff accelerator at BNL. The primary objective of our studies is to elucidate the influence of high vs low energy deposition on track structure, delta ray contribution and resulting biological responses. These low energy ions are of special relevance as these energies may occur following absorption through the spacecraft and shielding materials in human tissues and nuclear fragments produced in tissues by high energy protons and neutrons. This study will help to verify the efficiency of these low energy particles and better understand how various cell types respond to them.

  1. Effects of selenite and chelating agents on mammalian thioredoxin reductase inhibited by mercury: implications for treatment of mercury poisoning.

    PubMed

    Carvalho, Cristina M L; Lu, Jun; Zhang, Xu; Arnér, Elias S J; Holmgren, Arne

    2011-01-01

    Mercury toxicity is a highly interesting topic in biomedicine due to the severe endpoints and treatment limitations. Selenite serves as an antagonist of mercury toxicity, but the molecular mechanism of detoxification is not clear. Inhibition of the selenoenzyme thioredoxin reductase (TrxR) is a suggested mechanism of toxicity. Here, we demonstrated enhanced inhibition of activity by inorganic and organic mercury compounds in NADPH-reduced TrxR, consistent with binding of mercury also to the active site selenolthiol. On treatment with 5 μM selenite and NADPH, TrxR inactivated by HgCl(2) displayed almost full recovery of activity. Structural analysis indicated that mercury was complexed with TrxR, but enzyme-generated selenide removed mercury as mercury selenide, regenerating the active site selenocysteine and cysteine residues required for activity. The antagonistic effects on TrxR inhibition were extended to endogenous antioxidants, such as GSH, and clinically used exogenous chelating agents BAL, DMPS, DMSA, and α-lipoic acid. Consistent with the in vitro results, recovery of TrxR activity and cell viability by selenite was observed in HgCl(2)-treated HEK 293 cells. These results stress the role of TrxR as a target of mercurials and provide the mechanism of selenite as a detoxification agent for mercury poisoning.

  2. Yeast and mammalian metabolism continuous monitoring by using pressure recording as an assessment technique for xenobiotic agent effects

    NASA Astrophysics Data System (ADS)

    Milani, Marziale; Ballerini, Monica; Ferraro, Lorenzo; Marelli, E.; Mazza, Francesca; Zabeo, Matteo

    2002-06-01

    Our work is devoted to the study of Saccharomyces cerevisiae and human lymphocytes cellular metabolism in order to develop a reference model to assess biological systems responses to chemical or physical agents exposure. CO2 variations inside test-tubes are measured by differential pressure sensors; pressure values are subsequently converted in voltage. The system allows to test up to 16 samples at the same time. Sampling manages up to 100 acquisitions per second. Values are recorded by a data acquisition card connected to a computer. This procedure leads to a standard curve (pressure variation versus time), typical of the cellular line, that describe cellular metabolism. The longest time lapse used is of 170 h. Different phases appear in this curve: an initial growth up to a maximum, followed by a decrement that leads to a typical depression (pressure value inside the test-tubes is lower than the initial one) after about 35 h from the beginning of yeast cells. The curve is reproducible within an experimental error of 4%. The analysis of many samples and the low cost of the devices allow a good statistical significance of the data. In particular as a test we will compare two sterilizing agents effects: UV radiation and amuchina.

  3. Numerical calculations for diffusion effects in the well-of-the-well culture system for mammalian embryos.

    PubMed

    Matsuura, Koji

    2014-06-01

    Recent studies suggest that the microenvironment and embryo density used during embryo culture considerably affect development to the blastocyst stage. High embryo density allows for autocrine secretions to diffuse to neighbouring embryos during group culture, with a positive effect on further development. A variation of group culture is the well-of-the-well (WOW) culture system, allowing for individual identification of embryos cultured in small holes in a microdroplet. Bovine blastocyst development is higher in the WOW culture system than in conventional group culture. To compare the concentration of chemical factors between conventional and WOW culture, a model was constructed to calculate the concentration of secreted factors based on Fick's second law of diffusion using spreadsheet software. Furthermore, model was used to determine the concentration of growth factors and waste materials adjacent to the embryo periphery. The results of these calculations suggest that the highest difference in the concentration of secreted small molecules and macromolecules was at the most two- to threefold, with the concentrations reduced more and diffusion kinetics facilitated to a greater extent in the WOW culture system. The average ratio of the concentration of secreted macromolecules (10nm diameter) around the embryos was also compared between systems with well widths of 0.1 and 0.3mm. The concentration of secreted materials surrounding embryos increased in a narrow tapered well. The findings suggest that the WOW culture system is better than conventional group culture because of the increased final concentration of autocrine factors and higher diffusion kinetics of waste materials.

  4. Effect of fluorine substitution on the interaction of lipophilic ions with the plasma membrane of mammalian cells.

    PubMed Central

    Kürschner, M; Nielsen, K; von Langen, J R; Schenk, W A; Zimmermann, U; Sukhorukov, V L

    2000-01-01

    The effects of the anionic tungsten carbonyl complex [W(CO)(5)SC(6)H(5)](-) and its fluorinated analog [W(CO)(5)SC(6)F(5)](-) on the electrical properties of the plasma membrane of mouse myeloma cells were studied by the single-cell electrorotation technique. At micromolar concentrations, both compounds gave rise to an additional antifield peak in the rotational spectra of cells, indicating that the plasma membrane displayed a strong dielectric dispersion. This means that both tungsten derivatives act as lipophilic ions that are able to introduce large amounts of mobile charges into the plasma membrane. The analysis of the rotational spectra allowed the evaluation not only of the passive electric properties of the plasma membrane and cytoplasm, but also of the ion transport parameters, such as the surface concentration, partition coefficient, and translocation rate constant of the lipophilic anions dissolved in the plasma membrane. Comparison of the membrane transport parameters for the two anions showed that the fluorine-substituted analog was more lipophilic, but its translocation across the plasma membrane was slower by at least one order of magnitude than that of the parent hydrogenated anion. PMID:10969010

  5. Bioimaging techniques for subcellular localization of plant hemoglobins and measurement of hemoglobin-dependent nitric oxide scavenging in planta.

    PubMed

    Hebelstrup, Kim H; Østergaard-Jensen, Erik; Hill, Robert D

    2008-01-01

    Plant hemoglobins are ubiquitous in all plant families. They are expressed at low levels in specific tissues. Several studies have established that plant hemoglobins are scavengers of nitric oxide (NO) and that varying the endogenous level of hemoglobin in plant cells negatively modulates bioactivity of NO generated under hypoxic conditions or during cellular signaling. Earlier methods for determination of hemoglobin-dependent scavenging in planta were based on measuring activity in whole plants or organs. Plant hemoglobins do not contain specific organelle localization signals; however, earlier reports on plant hemoglobin have demonstrated either cytosolic or nuclear localization, depending on the method or cell type investigated. We have developed two bioimaging techniques: one for visualization of hemoglobin-catalyzed scavenging of NO in specific cells and another for visualization of subcellular localization of green fluorescent protein-tagged plant hemoglobins in transformed Arabidopsis thaliana plants.

  6. A model for mammalian cochlear hair cell differentiation in vitro: effects of retinoic acid on cytoskeletal proteins and potassium conductances.

    PubMed

    Helyer, R; Cacciabue-Rivolta, D; Davies, D; Rivolta, M N; Kros, C J; Holley, M C

    2007-02-01

    We have established a model for the in-vitro differentiation of mouse cochlear hair cells and have used it to explore the influence of retinoic acid on proliferation, cytoskeletal proteins and voltage-gated potassium conductances. The model is based on the conditionally immortal cell line University of Sheffield/ventral otocyst-epithelial cell line clone 36 (US/VOT-E36), derived from ventral otic epithelial cells of the mouse at embryonic day 10.5 and transfected with a reporter for myosin VIIa. Retinoic acid did not increase cell proliferation but led to up-regulation of myosin VIIa and formation of prominent actin rings that gave rise to numerous large, linear actin bundles. Cells expressing myosin VIIa had larger potassium conductances and did not express the cyclin-dependent kinase inhibitor p27(kip1). US/VOT-E36 endogenously expressed the voltage-gated potassium channel alpha-subunits Kv1.3 and Kv2.1, which we subsequently identified in embryonic and neonatal hair cells in both auditory and vestibular sensory epithelia in vivo. These subunits could underlie the embryonic and neonatal delayed-rectifiers recorded in nascent hair cells in vivo. Kv2.1 was particularly prominent on the basolateral membrane of cochlear inner hair cells. Kv1.3 was distributed throughout all hair cells but tended to be localized to the cuticular plates. US/VOT-E36 recapitulates a coherent pattern of cell differentiation under the influence of retinoic acid and will provide a convenient model for screening the effects of other extrinsic factors on the differentiation of cochlear epithelial cell types in vitro.

  7. Effects of growth factors on the hair cells after ototoxic treatment of the neonatal mammalian cochlea in vitro.

    PubMed

    Romand, R; Chardin, S

    1999-04-17

    The aim of this study was to test the possible regenerative potential of several molecules and growth factors such as retinoic acid (RA), insulin, epidermal growth factor (EGF) and transforming growth factors alpha (TGFalpha) and beta (TGFbeta) on the neonatal cochlea in vitro after neomycin intoxication. Our studies show that cochlear sensory epithelium behaves differently while maintained in various culture conditions, although we did not observe regeneration whatever the molecules or growth factors tested. The ototoxic action of neomycin in vitro produced a specific death of hair cells, except in the apical region. Organ of Corti of rats 3 days after birth always presented two regions that responded differently to the antibiotic: a widespread scar region extending from the basal cochlea up to the beginning of the apical turn, where most hair cells had disappeared, and a second region called the resistance region localized in the apex, and which was more or less developed depending on culture conditions. The length of the resistance region was modulated by molecules or growth factors added to the feeding solution suggesting that some of them could produce a protective action on hair cells against neomycin. Slight protection effects may be found with RA and insulin, however, the most definite protection results from the combination of insulin with TGFalpha as shown by the large increase in the length of the resistance region compared to organ of Corti treated with antibiotic alone. The tested molecules and growth factors did not promote cochlear hair cell regeneration in vitro after neomycin treatment, however some of them may offer a protective action against ototoxicity.

  8. Genome regulation in mammalian cells.

    PubMed

    Puck, T T; Krystosek, A; Chan, D C

    1990-05-01

    A theory is presented proposing that genetic regulation in mammalian cells is at least a two-tiered effect; that one level of regulation involves the transition between gene exposure and sequestration; that normal differentiation requires a different spectrum of genes to be exposed in each separate state of differentiation; that the fiber systems of the cell cytoskeleton and the nuclear matrix together control the degree of gene exposure; that specific phosphorylation of these elements causes them to assume a different organizational network and to impose a different pattern of sequestration and exposure on the elements of the genome; that the varied gene phosphorylation mechanisms in the cell are integrated in this function; that attachment of this network system to specific parts of the chromosomes brings about sequestration or exposure of the genes in their neighborhood in a fashion similar to that observed when microtubule elements attach through the kinetochore to the centromeric DNA; that one function of repetitive sequences is to serve as elements for the final attachment of this fibrous network to the specific chromosomal loci; and that at least an important part of the calcium manifestation as a metabolic trigger of different differentiation states involves its acting as a binding agent to centers of electronegativity, in particular proteins and especially phosphorylated groups, so as to change the conformation of the fiber network that ultimately controls gene exposure in the mammalian cell. It would appear essential to determine what abnormal gene exposures and sequestrations are characteristic of each type of cancer; which agonists, if any, will bring about reverse transformation; and whether these considerations can be used in therapy.

  9. Effects of phorbol ester on contraction, intracellular pH and intracellular Ca2+ in isolated mammalian ventricular myocytes.

    PubMed Central

    MacLeod, K T; Harding, S E

    1991-01-01

    1. We have investigated the actions of certain phorbol esters on the intracellular pH, intracellular Ca2+ and contractility of isolated rat and guinea-pig cardiac myocytes. Intracellular pH was measured using 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF) and intracellular Ca2+ was measured using Fura-2. 2. Application of the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (also called phorbol 12-myristate 13-acetate) (TPA) (which activates protein kinase C) to rat cardiac myocytes significantly increased cell shortening by 116 +/- 34% (n = 8) (p less than 0.02). The rate of change of cell length during contraction (i.e. +dL/dt) increased from 67.2 +/- 8.7 microns/s to 127.7 +/- 14.1 microns/s (n = 7). The rate of change of cell length during relaxation (-dL/dt) increased from 55.8 +/- 7.4 microns/s to 118.9 +/- 12.1 microns/s (n = 7). Time to peak shortening was unchanged. 3. Application of 4 alpha-phorbol 12,13-didecanoate, which does not activate protein kinase C, did not affect rat myocyte contractility. An insignificant decrease in contractility (by 7.5 +/- 7.5%) was observed (n = 5). The positive inotropic effect of TPA may therefore be evoked through an activation of protein kinase C. 4. In rat myocytes we have measured the changes of pHi and contractility (cell shortening) during an alkalosis and acidosis induced by exposure to and subsequent removal of NH4Cl both in the presence and absence of TPA. Recovery times from an acid load were significantly (p less than 0.05) enhanced by 15.1 +/- 6.9% (n = 13) in the presence of TPA. Recovery times of cell shortening were also more rapid (p less than 0.05) by an average of 59.1 +/- 10.6% (n = 5) in the presence of TPA. Recovery times were unchanged in the presence of 4-phorbol 12,13-didecanoate (which does not activate protein kinase C). 5. Since pHi recovery of an isolated myocyte from an acid load is partially inhibited by the presence of 1 mM-amiloride and inhibited by removing extracellular Na

  10. [Research on Early Diagnosis of Gastric Cancer by the Surface Enhanced Raman Spectroscopy of Human Hemoglobin].

    PubMed

    Wang, Wei; Pan, Zhi-feng; Tang, Wei-yue; Li, Yun-tao; Fan, Chun-zhen

    2015-12-01

    Early diagnosis have great positive effect on the treatment of gastric cancer patients. Raman spectroscopy can provide a useful monitor for hemoglobin dynamics. Besides, Raman spectroscopy has notable advantages in the fields of abnormal hemoglobin diagnosis, hemoglobin oxygen saturation deter mination and blood methemoglobin analysis. In this paper, novel silver colloid was synthesized by microwave heated method. The surface enhanced Raman spectrums of hemoglobin from 11 normal persons and 20 gastric cancer patients are measured and analyzed in order to obtain spectrums which are high repeatability and characteristic peaks protruding. By analyzing the assignations of the SERS bands, it found that the content of asparagine, tyrosine and phenylalanine in the hemoglobin are significantly lower than healthy people. Discussing the structure of hemoglobin, when hemoglobin combines with oxygen, Fe²⁺ is in a low spin state, ionic radius shrinks and moves 0. 075 nm and fall into the pore in the middle of the heme porphyrin ring plane. This spatial variation affects F8His connected with the iron, will narrow the gap between the globin in the two strands of the helix, as a result, HC2 tyrosine pushed out of the void. Using this mechanism, the absorption peak of 1 560 cm⁻¹ confirmed that the tyrosine content in patients with gastric cancer was lower than that of normal people. Principal component analysis(PCA) is employed to get a three-dimensional scatter plot of PC scores for the health and cancer groups, and it can be learned that they are distributed in separate areas. By using the method of discriminate analysis, it is found that the diagnostic algorithm separates the two groups with sensitivity of 90.0% and diagnostic specificity of 90.9%, the overall diagnostic accuracy was 90.3%. The results from this exploratory study demonstrate that, SERS detection of oxyhemoglobin combined with multivariate analysis would be an effective method for early diagnosis of gastric

  11. Computation of the unsteady facilitated transport of oxygen in hemoglobin

    NASA Technical Reports Server (NTRS)

    Davis, Sanford

    1990-01-01

    The transport of a reacting permeant diffusing through a thin membrane is extended to more realistic dissociation models. A new nonlinear analysis of the reaction-diffusion equations, using implicit finite-difference methods and direct block solvers, is used to study the limits of linearized and equilibrium theories. Computed curves of molecular oxygen permeating through hemoglobin solution are used to illustrate higher-order reaction models, the effect of concentration boundary layers at the membrane interfaces, and the transient buildup of oxygen flux.

  12. Architecture of mammalian respiratory complex I.

    PubMed

    Vinothkumar, Kutti R; Zhu, Jiapeng; Hirst, Judy

    2014-11-06

    Complex I (NADH:ubiquinone oxidoreductase) is essential for oxidative phosphorylation in mammalian mitochondria. It couples electron transfer from NADH to ubiquinone with proton translocation across the energy-transducing inner membrane, providing electrons for respiration and driving ATP synthesis. Mammalian complex I contains 44 different nuclear- and mitochondrial-encoded subunits, with a combined mass of 1 MDa. The 14 conserved 'core' subunits have been structurally defined in the minimal, bacterial complex, but the structures and arrangement of the 30 'supernumerary' subunits are unknown. Here we describe a 5 Å resolution structure of complex I from Bos taurus heart mitochondria, a close relative of the human enzyme, determined by single-particle electron cryo-microscopy. We present the structures of the mammalian core subunits that contain eight iron-sulphur clusters and 60 transmembrane helices, identify 18 supernumerary transmembrane helices, and assign and model 14 supernumerary subunits. Thus, we considerably advance knowledge of the structure of mammalian complex I and the architecture of its supernumerary ensemble around the core domains. Our structure provides insights into the roles of the supernumerary subunits in regulation, assembly and homeostasis, and a basis for understanding the effects of mutations that cause a diverse range of human diseases.

  13. Architecture of mammalian respiratory complex I

    PubMed Central

    Hirst, Judy

    2014-01-01

    Complex I (NADH:ubiquinone oxidoreductase) is essential for oxidative phosphorylation in mammalian mitochondria. It couples electron transfer from NADH to ubiquinone with proton translocation across the energy-transducing inner membrane, providing electrons for respiration and driving ATP synthesis. Mammalian complex I contains 44 different nuclear- and mitochondrial-encoded subunits, with a combined mass of 1 MDa. The fourteen conserved ‘core’ subunits have been structurally defined in the minimal, bacterial complex, but the structures and arrangement of the 30 ‘supernumerary’ subunits are unknown. Here, we describe a 5 Å resolution structure of complex I from Bos taurus heart mitochondria, a close relative of the human enzyme, determined by single-particle electron cryo-microscopy. We present the structures of the mammalian core subunits that contain eight iron-sulphur clusters and 60 transmembrane helices, identify 18 supernumerary transmembrane helices, and assign and model 14 supernumerary subunits. Thus, we significantly advance knowledge of the structure of mammalian complex I and the architecture of its supernumerary ensemble around the core domains. Our structure provides insights into the roles of the supernumerary subunits in regulation, assembly and homeostasis, and a basis for understanding the effects of mutations that cause a diverse range of human diseases. PMID:25209663

  14. Structure of mammalian respiratory complex I

    PubMed Central

    Hirst, Judy

    2016-01-01

    Complex I (NADH:ubiquinone oxidoreductase), one of the largest membrane-bound enzymes in the cell, powers ATP synthesis in mammalian mitochondria by using the reducing potential of NADH to drive protons across the inner membrane. Mammalian complex I1 contains 45 subunits, comprising 14 core subunits that house the catalytic machinery and are conserved from bacteria to humans, and a mammalian-specific cohort of 31 supernumerary subunits1,2. Knowledge about the structures and functions of the supernumerary subunits is fragmentary. Here, we describe a 4.2 Å resolution single-particle cryoEM structure of complex I from Bos taurus. We locate and model all 45 subunits to provide the entire structure of the mammalian complex. Furthermore, computational sorting of the particles identified different structural classes, related by subtle domain movements, which reveal conformationally-dynamic regions and match biochemical descriptions of the ‘active-to-deactive’ enzyme transition that occurs during hypoxia3,4. Thus, our structures provide a foundation for understanding complex I assembly5 and the effects of mutations that cause clinically-relevant complex I dysfunctions6, insights into the structural and functional roles of the supernumerary subunits, and new information on the mechanism and regulation of catalysis. PMID:27509854

  15. Direct sGC Activation Bypasses NO Scavenging Reactions of Intravascular Free Oxy-Hemoglobin and Limits Vasoconstriction

    PubMed Central

    Tabima, D. Marcela; Specht, Patricia A.C.; Tejero, Jesús; Champion, Hunter C.; Kim-Shapiro, Daniel B.; Baust, Jeff; Mik, Egbert G.; Hildesheim, Mariana; Stasch, Johannes-Peter; Becker, Eva-Maria; Truebel, Hubert

    2013-01-01

    Abstract Aims: Hemoglobin-based oxygen carriers (HBOC) provide a potential alternative to red blood cell (RBC) transfusion. Their clinical application has been limited by adverse effects, in large part thought to be mediated by the intravascular scavenging of the vasodilator nitric oxide (NO) by cell-free plasma oxy-hemoglobin. Free hemoglobin may also cause endothelial dysfunction and platelet activation in hemolytic diseases and after transfusion of aged stored RBCs. The new soluble guanylate cyclase (sGC) stimulator Bay 41-8543 and sGC activator Bay 60-2770 directly modulate sGC, independent of NO bioavailability, providing a potential therapeutic mechanism to bypass hemoglobin-mediated NO inactivation. Results: Infusions of human hemoglobin solutions and the HBOC Oxyglobin into rats produced a severe hypertensive response, even at low plasma heme concentrations approaching 10 μM. These reactions were only observed for ferrous oxy-hemoglobin and not analogs that do not rapidly scavenge NO. Infusions of L-NG-Nitroarginine methyl ester (L-NAME), a competitive NO synthase inhibitor, after hemoglobin infusion did not produce additive vasoconstriction, suggesting that vasoconstriction is related to scavenging of vascular NO. Open-chest hemodynamic studies confirmed that hypertension occurred secondary to direct effects on increasing vascular resistance, with limited negative cardiac inotropic effects. Intravascular hemoglobin reduced the vasodilatory potency of sodium nitroprusside (SNP) and sildenafil, but had no effect on vasodilatation by direct NO-independent activation of sGC by BAY 41-8543 and BAY 60-2770. Innovation and Conclusion: These data suggest that both sGC stimulators and sGC activators could be used to restore cyclic guanosine monophosphate-dependent vasodilation in conditions where cell-free plasma hemoglobin is sufficient to inhibit endogenous NO signaling. Antioxid. Redox Signal. 19, 2232–2243. PMID:23697678

  16. Effect of positive feedback loops on the robustness of oscillations in the network of cyclin-dependent kinases driving the mammalian cell cycle.

    PubMed

    Gérard, Claude; Gonze, Didier; Goldbeter, Albert

    2012-09-01

    The transitions between the G(1), S, G(2) and M phases of the mammalian cell cycle are driven by a network of cyclin-dependent kinases (Cdks), whose sequential activation is regulated by intertwined negative and positive feedback loops. We previously proposed a detailed computational model for the Cdk network, and showed that this network is capable of temporal self-organization in the form of sustained oscillations, which govern ordered progression through the successive phases of the cell cycle [Gérard and Goldbeter (2009) Proc Natl Acad Sci USA 106, 21643-21648]. We subsequently proposed a skeleton model for the cell cycle that retains the core regulatory mechanisms of the detailed model [Gérard and Goldbeter (2011) Interface Focus 1, 24-35]. Here we extend this skeleton model by incorporating Cdk regulation through phosphorylation/dephosphorylation and by including the positive feedback loops that underlie the dynamics of the G(1)/S and G(2)/M transitions via phosphatase Cdc25 and via phosphatase Cdc25 and kinase Wee1, respectively. We determine the effects of these positive feedback loops and ultrasensitivity in phosphorylation/dephosphorylation on the dynamics of the Cdk network. The multiplicity of positive feedback loops as well as the existence of ultrasensitivity promote the occurrence of bistability and increase the amplitude of the oscillations in the various cyclin/Cdk complexes. By resorting to stochastic simulations, we further show that the presence of multiple, redundant positive feedback loops in the G(2)/M transition of the cell cycle markedly enhances the robustness of the Cdk oscillations with respect to molecular noise.

  17. Hemoglobin Function in Stored Blood.

    DTIC Science & Technology

    1974-08-01

    and inosine with or without methylene blue , showed that the pH 6.4 to 7.2 preservatives afforded the best DPG maintenance. 2. Experiments with CPD...adenine-inosine with and without uiethylene blue indicate that the methylene blue effect is dependent on the presence of inosine for maintenance of 2,3...this country and in transfusion practice in several countries in Europe for a number of years. It in believed that the work involving methylene - blue represents

  18. Structural and redox behavior of OxyVita, a zero-linked polymeric hemoglobin: comparison with natural acellular polymeric hemoglobins.

    PubMed

    Harrington, John P; Orlik, Kseniya; Orlig, Kseniya; Zito, Samantha L; Wollocko, Jacek; Wollocko, Hanna

    2010-04-01

    A zero-linked polymeric hemoglobin (OxyVita Hb) has been developed for application as an acellular therapeutic hemoglobin-based-oxygen-carrier (HBOC). For effective and safe oxygen binding, transport and delivery, an HBOC must meet essential molecular requirements related to its structural integrity and redox stability. OxyVita is a super polymer possessing an average M.wt. of 17 x 10(6) Da. Structural integrity was determined by unfolding studies of OxyVita in the presence of increasing concentrations of urea. The unfolding midpoints (D(1/2)) of different preparations of OxyVita (solution and powder forms) were compared to Lumbricus Hb (LtHb) and Arenicola Hb (ArHb), natural acellular polymeric hemoglobins, which are serving as models for an effective and safe acellular HBOC. Reduction studies of OxyVita Hb using endogenous reducing agents were also investigated. Results from these studies indicate that: 1) OxyVita Hb exhibits greater resistance to conformational change than either LtHb or ArHb in the reduced (oxyHb) state; and 2) the reduction of met OxyVita Hb to oxyHb occurs slowly in the presence of either ascorbic acid (70% reduction in 560 min.) or beta-NADH (40% reduction in 90 min.). These studies provide consistent evidence that OxyVita Hb possesses physiochemical properties that exhibit structural integrity and redox behavior necessary for functioning as an effective and safe HBOC within clinical applications. These results are in agreement with observations made by other investigators as to the reduction in heme-loss of OxyVita Hb, essential for the reversible binding/release of molecular oxygen within the circulatory system.

  19. Mammalian clock output mechanisms.

    PubMed

    Kalsbeek, Andries; Yi, Chun-Xia; Cailotto, Cathy; la Fleur, Susanne E; Fliers, Eric; Buijs, Ruud M

    2011-06-30

    In mammals many behaviours (e.g. sleep-wake, feeding) as well as physiological (e.g. body temperature, blood pressure) and endocrine (e.g. plasma corticosterone concentration) events display a 24 h rhythmicity. These 24 h rhythms are induced by a timing system that is composed of central and peripheral clocks. The highly co-ordinated output of the hypothalamic biological clock not only controls the daily rhythm in sleep-wake (or feeding-fasting) behaviour, but also exerts a direct control over many aspects of hormone release and energy metabolism. First, we present the anatomical connections used by the mammalian biological clock to enforce its endogenous rhythmicity on the rest of the body, especially the neuro-endocrine and energy homoeostatic systems. Subsequently, we review a number of physiological experiments investigating the functional significance of this neuro-anatomical substrate. Together, this overview of experimental data reveals a highly specialized organization of connections between the hypothalamic pacemaker and neuro-endocrine system as well as the pre-sympathetic and pre-parasympathetic branches of the autonomic nervous system.

  20. The Mammalian Septin Interactome

    PubMed Central

    Neubauer, Katharina; Zieger, Barbara

    2017-01-01

    Septins are GTP-binding and membrane-interacting proteins with a highly conserved domain structure involved in various cellular processes, including cytoskeleton organization, cytokinesis, and membrane dynamics. To date, 13 different septin genes have been identified in mammals (SEPT1 to SEPT12 and SEPT14), which can be classified into four distinct subgroups based on the sequence homology of their domain structure (SEPT2, SEPT3, SEPT6, and SEPT7 subgroup). The family members of these subgroups have a strong affinity for other septins and form apolar tri-, hexa-, or octameric complexes consisting of multiple septin polypeptides. The first characterized core complex is the hetero-trimer SEPT2-6-7. Within these complexes single septins can be exchanged in a subgroup-specific manner. Hexamers contain SEPT2 and SEPT6 subgroup members and SEPT7 in two copies each whereas the octamers additionally comprise two SEPT9 subgroup septins. The various isoforms seem to determine the function and regulation of the septin complex. Septins self-assemble into higher-order structures, including filaments and rings in orders, which are typical for different cell types. Misregulation of septins leads to human diseases such as neurodegenerative and bleeding disorders. In non-dividing cells such as neuronal tissue and platelets septins have been associated with exocytosis. However, many mechanistic details and roles attributed to septins are poorly understood. We describe here some important mammalian septin interactions with a special focus on the clinically relevant septin interactions. PMID:28224124

  1. Universal metastability of sickle hemoglobin polymerization

    NASA Astrophysics Data System (ADS)

    Weng, Weijun

    Sickle hemoglobin (HbS) is a natural mutation of the normal hemoglobin (HbA) found in the red blood cells of human body. Polymerization of HbS occurs when the concentration of deoxyHbS exceeds a well-defined solubility, which is the underlying cause of the Sickle Cell Disease. It has long been assumed that thermodynamic equilibrium is reached when polymerization comes to an end. However, in this thesis we demonstrate that in confined volume as well as in bulk solution, HbS polymerization terminates prematurely, leaving the solution in a metastable state. A newly developed Reservoir method as well as modulated excitation method were adopted for the study. This discovery of universal metastability gives us new insights into understanding the mechanism of sickle cell disease.

  2. [Abnormal hemoglobins in Negroid Ecuadorian populations].

    PubMed

    Jara, N O; Guevara Espinoza, A; Guderian, R H

    1989-02-01

    The prevalence of hemoglobinopathies was determined in the black race located in two distinct geographical areas in Ecuador; in the coastal province of Esmeraldas, particularly the Santiago basin (Rio Cayapas and Rio Onzoles) and in the province of Imbabura, particularly in the intermoutain valley, Valle de Chota. A total of 2038 blood samples were analyzed, 1734 in Esmeraldas and 304 in Inbabura, of which 23.2% (473 individuals) were found to be carriers of abnormal hemoglobins, 25.4% (441) in Esmeraldas and 10.5% (32) in Imbabura. The abnormal hemoglobins found in Esmeraldas were Hb AS (19.2%), Hb AC (5.0%), Hb SS (0.6%) and Hb SC (0.5%) while in Imbabura only Hb AS (9.5%) and Hb AC (0.9%) were found. The factors that could influence the difference in prevalence found in the two geographical areas are discussed.

  3. A Rosetta stone of mammalian genetics.

    PubMed

    Nadeau, J H; Grant, P L; Mankala, S; Reiner, A H; Richardson, J E; Eppig, J T

    1995-01-26

    The Mammalian Comparative Database provides genetic maps of mammalian species. Comparative maps are valuable aids for predicting linkages, developing animal models and studying genome organization and evolution.

  4. Carboxyalkylated Hemoglobin as a Potential Blood Substitute.

    DTIC Science & Technology

    1987-01-24

    I- 1.8 MICROCOpy RESOLUTION TEST CHART NAT OWAI BURErAU Of STANDARDS 1963-A OliC FIE COPJ Alit D CARBOXYALKYLATED HEMOGLOBIN AS AN POTENTIAL BLOOD...valine derivatives as the monocarboxymethyl and dicarboxymethyl derivatives, respectively. These derivatives are ninhydrin -negative. The lysine...derivative, wLich was eluted in 1 M acetic acid, was applied to an amino acid analyzer since it is ninhydrin -positive. Its position coincided with that of

  5. Stem Cells in Mammalian Gonads.

    PubMed

    Wu, Ji; Ding, Xinbao; Wang, Jian

    Stem cells have great value in clinical application because of their ability to self-renew and their potential to differentiate into many different cell types. Mammalian gonads, including testes for males and ovaries for females, are composed of germline and somatic cells. In male mammals, spermatogonial stem cells maintain spermatogenesis which occurs continuously in adult testis. Likewise, a growing body of evidence demonstrated that female germline stem cells could be found in mammalian ovaries. Meanwhile, prior studies have shown that somatic stem cells exist in both testes and ovaries. In this chapter, we focus on mammalian gonad stem cells and discuss their characteristics as well as differentiation potentials.

  6. The German ISS-experiment Cellular Responses to Radiation in Space (CERASP): The effects of single and combined space flight conditions on mammalian cells

    NASA Astrophysics Data System (ADS)

    Hellweg, C. E.; Thelen, M.; Arenz, A.; Baumstark-Khan, C.

    The combined action of ionizing radiation and microgravity will continue to influence future manned space missions, with special risks for astronauts on the Moon surface or for long duration missions to Mars. There is increasing evidence that basic cellular functions are sensitive not only to radiation but also to microgravity. Previous space flight experiments gave contradictory results: from inhibition of DNA repair by microgravity to enhancement, whereas others did not detect any influence of microgravity on repair. At the Radiation Biology Department of the German Aerospace Center (DLR), recombinant bacterial and mammalian cell systems were developed as reporters for cellular signal transduction modulation by genotoxic environmental conditions. The space experiment “Cellular Responses to Radiation in Space” (CERASP) to be performed at the International Space Station (ISS) will make use of such reporter cell lines thereby supplying basic information on the cellular response to radiation applied in microgravity. One of the biological endpoints will be survival reflected by radiation-dependent reduction of constitutive expression of the enhanced variant of green fluorescent protein (EGFP). A second end-point will be gene activation by space flight conditions in mammalian cells, based on fluorescent promoter reporter systems using the destabilized d2EGFP variant. The promoter element to be investigated reflects the activity of the nuclear factor kappa B (NF-κB) pathway. The NF-κB family of proteins plays a major role in the inflammatory and immune response, cell proliferation and differentiation, apoptosis and tumor genesis. Results obtained with X-rays and accelerated heavy ions produced at the French heavy ion accelerator GANIL imply that densely ionizing radiation has a stronger potential to activate NF-κB dependent gene expression than sparsely ionizing radiation. The correlation of NF-κB activation to negative regulation of apoptosis could favor

  7. Evaluation and interference study of hemoglobin A1c measured by turbidimetric inhibition immunoassay.

    PubMed

    Chang, J; Hoke, C; Ettinger, B; Penerian, G

    1998-03-01

    The technical performance of the turbidimetric immunoinhibition (TI) assay for hemoglobin (Hb) A1c (Tina-quant Hb A1c, Boehringer Mannheim, Indianapolis, Ind) was evaluated by using the BM/Hitachi 911 analyzer. Intra-assay imprecision was less than 2.7%, and interassay imprecision was less than 2.8% as measured by coefficient of variation. In 93 subjects with diabetes who did not have hemoglobin variants, results of the TI assay for Hb A1c correlated strongly with those obtained by using a high-performance liquid chromatography analyzer (Diamat, BioRad Laboratories, Hercules, Calif). Among 241 subjects who had or did not have hemoglobin variants, the TI assay for Hb A1c correlated strongly with results of affinity chromatography for total glycated hemoglobin (Glyc-Affin GHb, IsoLab, Akron, Ohio). We also studied the effect of various percentages of hemoglobin S, C, E, and F on the accuracy of the TI Hb A1c assay. Only high hemoglobin F percentages caused interference. More than 14 times as many samples can be analyzed per hour by using the TI Hb A1c assay than can be analyzed by using the HPLC assay. For high-volume reference laboratories, using the fully automated TI Hb A1c assay to monitor glycemic control in patients with diabetes may be preferable to using the conventional ion-exchange high-performance liquid chromatography Hb A1c assay because the TI assay measures Hb A1c more accurately in patients with diabetes who have hemoglobin variants, and it requires less time.

  8. Human hemoglobin structural and functional alterations and heme degradation upon interaction with benzene: A spectroscopic study.

    PubMed

    Hosseinzadeh, Reza; Moosavi-Movahedi, Ali Akbar

    2016-03-15

    Here, the effect of benzene on hemoglobin structure, stability and heme prosthetic group integrity was studied by different methods. These included UV-vis absorption spectrophotometry, normal and synchronous fluorescence techniques, and differential scanning calorimetry (DSC). Our results indicated that benzene has high hemolytic potential even at low concentrations. The UV-vis spectroscopic results demonstrated that benzene altered both the globin chain and the heme prosthetic group of hemoglobin increasing met- and deoxy-Hb, while decreasing oxy-Hb. However, with increasing benzene the concentration of all species decreased due to heme destruction. The spectrophotometric results show that benzene has a high potential for penetrating the hydrophobic pocket of hemoglobin. These results were consistent with the molecular docking simulation results of benzene-hHb. Aggregation and thermal denaturation studies show that the increased benzene concentration induced hemoglobin aggregation with a decrease in stability, which is consistent with the DSC results. Conventional fluorescence spectroscopy revealed that the heme degradation species were produced in the presence of benzene. The results of constant wavelength synchronous fluorescence spectroscopy (CWSFS) indicated that at least five heme-degraded species were produced. Together, our results indicated that benzene has adverse effects on hemoglobin structure and function, and heme degradation.

  9. Human hemoglobin structural and functional alterations and heme degradation upon interaction with benzene: A spectroscopic study

    NASA Astrophysics Data System (ADS)

    Hosseinzadeh, Reza; Moosavi-Movahedi, Ali Akbar

    2016-03-01

    Here, the effect of benzene on hemoglobin structure, stability and heme prosthetic group integrity was studied by different methods. These included UV-vis absorption spectrophotometry, normal and synchronous fluorescence techniques, and differential scanning calorimetry (DSC). Our results indicated that benzene has high hemolytic potential even at low concentrations. The UV-vis spectroscopic results demonstrated that benzene altered both the globin chain and the heme prosthetic group of hemoglobin increasing met- and deoxy-Hb, while decreasing oxy-Hb. However, with increasing benzene the concentration of all species decreased due to heme destruction. The spectrophotometric results show that benzene has a high potential for penetrating the hydrophobic pocket of hemoglobin. These results were consistent with the molecular docking simulation results of benzene-hHb. Aggregation and thermal denaturation studies show that the increased benzene concentration induced hemoglobin aggregation with a decrease in stability, which is consistent with the DSC results. Conventional fluorescence spectroscopy revealed that the heme degradation species were produced in the presence of benzene. The results of constant wavelength synchronous fluorescence spectroscopy (CWSFS) indicated that at least five heme-degraded species were produced. Together, our results indicated that benzene has adverse effects on hemoglobin structure and function, and heme degradation.

  10. Maturation of the mammalian secretome

    PubMed Central

    Simpson, Jeremy C; Mateos, Alvaro; Pepperkok, Rainer

    2007-01-01

    A recent use of quantitative proteomics to determine the constituents of the endoplasmic reticulum and Golgi complex is discussed in the light of other available methodologies for cataloging the proteins associated with the mammalian secretory pathway. PMID:17472737

  11. Mammalian DNA Repair. Final Report

    SciTech Connect

    2003-01-24

    The Gordon Research Conference (GRC) on Mammalian DNA Repair was held at Harbortown Resort, Ventura Beach, CA. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  12. Haptoglobin genotype modulates the balance of Th1/Th2 cytokines produced by macrophages exposed to free hemoglobin.

    PubMed

    Guetta, Julia; Strauss, Merav; Levy, Nina S; Fahoum, Lana; Levy, Andrew P

    2007-03-01

    The haptoglobin genotype has been demonstrated to be an independent risk factor for CVD in multiple epidemiological studies. The primary function of haptoglobin is to mitigate the deleterious effects of extracorpuscular hemoglobin. We sought to determine if the protein products of the two haptoglobin alleles differed in their ability to modulate the cytokine profile produced by macrophages in response to hemoglobin. Peripheral blood mononuclear cells were isolated from normal human volunteers and cultured in the presence of complexes formed by the protein products of the two different haptoglobin alleles with hemoglobin. The release of specific cytokines in the conditioned media of these cells was assessed by ELISA. We found that the haptoglobin 1 allele protein product-hemoglobin complex stimulated the secretion of significantly more Il-6 and Il-10 than the haptoglobin 2 allele protein product-hemoglobin complex. We demonstrate that the release of these cytokines is dependent on the liganding of the haptoglobin-hemoglobin complex to the CD163 receptor and the activity of casein kinase II. Haptoglobin genotype modulates the balance of inflammatory (Th1) and anti-inflammatory (Th2) cytokines produced by macrophages exposed to free hemoglobin. This may have implications in understanding inter-individual differences in the inflammatory response to hemorrhage.

  13. Hypergravity signal transduction and gene expression in cultured mammalian cells

    NASA Technical Reports Server (NTRS)

    Kumei, Y.; Whitson, P. A.

    1994-01-01

    A number of studies have been conducted during space flight and with clinostats and centrifuges, suggesting that gravity effects the proliferation and differentiation of mammalian cells in vitro. However, little is known about the mechanisms by which mammalian cells respond to changes in gravitational stress. This paper summarizes studies designed to clarify the effects of hypergravity on the cultured human HeLa cells and to investigate the mechanism of hypergravity signal transduction in these cells.

  14. Carbon monoxide binding by hemoglobin and myoglobin under photodissociating conditions.

    PubMed

    Brunori, M; Bonaventura, J; Bonaventura, C; Antonini, E; Wyman, J

    1972-04-01

    Carbon monoxide binding by myoglobin and hemoglobin has been studied under conditions of constant illumination. For hemoglobin, the homotropic heme-heme interaction (cooperativity) and the heterotropic Bohr effect are invariant with light intensity over a 1000-fold change of c((1/2)). The dissociation constant, measured as c((1/2)), increases linearly with light intensity, indicating that photodissociation is a one-quantum process. At sufficiently high illumination the apparent enthalpy of ligand binding becomes positive, although in the absence of light it is known to be negative. This finding indicates that light acts primarily by increasing the "off" constants by an additive factor. The invariance of both cooperativity and Bohr effect raises a perplexing issue. It would appear to demand either that the "off" constants for the various elementary steps are all alike (which is contrary to current ideas) or that the additive factor is in each case proportional to the particular "off" constant to which it is added (a seemingly improbable alternative).

  15. Hemoglobin optimization and transfusion strategies in patients undergoing cardiac surgery.

    PubMed

    Najafi, Mahdi; Faraoni, David

    2015-07-26

    Although red blood cells (RBCs) transfusion is sometimes associated with adverse reactions, anemia could also lead to increased morbidity and mortality in high-risk patients. For these reasons, the definition of perioperative strategies that aims to detect and treat preoperative anemia, prevent excessive blood loss, and define "optimal" transfusion algorithms is crucial. Although the treatment with preoperative iron and erythropoietin has been recommended in some specific conditions, several controversies exist regarding the benefit-to-risk balance associated with these treatments. Further studies are needed to better define the indications, dosage, and route of administration for preoperative iron with or without erythropoietin supplementation. Although restrictive transfusion strategies in patients undergoing cardiac surgery have been shown to effectively reduce the incidence and the amount of RBCs transfusion without increase in side effects, some high-risk patients (e.g., symptomatic acute coronary syndrome) could benefit from higher hemoglobin concentrations. Despite all efforts made last decade, a significant amount of work remains to be done to improve hemoglobin optimization and transfusion strategies in patients undergoing cardiac surgery.

  16. Hemoglobin Status Associate with Performance IQ but not Verbal IQ in Chinese Pre-school Children

    PubMed Central

    Ai, Yuexian; Zhao, Sophie R.; Zhou, Guoping; Ma, Xiaoyang; Liu, Jianghong

    2012-01-01

    Background Despite the body of literature that links anemia with poorer cognition in children and the evidence that the severity of the effects of anemia on children’s cognition vary in different populations, few studies have investigated the effects of anemia on the cognitive development of Chinese children. Study Design This longitudinal cohort includes 171 children from a developing region of China. Hemoglobin and iron levels were taken when the children were 4 years old. At age 6, the children’s cognition was tested with Chinese WPPSI. Psychosocial information was also used in analyses. Results Results showed that the children who had low Hb levels had significantly lower scores in PIQ, but not VIQ. Although blood Fe levels were not shown to moderate the link between hemoglobin levels and IQ, we found children who performed the best on IQ tests exhibited low iron levels concurrent with high hemoglobin levels, whereas the group who performed the worst exhibited high iron but low hemoglobin levels. We also found that psychosocial adversity did not differ significantly between children who had normal or low hemoglobin levels, although the effect of hemoglobin on PIQ became only suggestive after controlling for psychosocial adversity, therefore the relationship is not causal but only a suggestive association. Conclusion Our findings are in agreement with literature on the negative effects of anemia on children’s cognition and point to the possibility that the portions of the brain associated with PIQ components are particularly affected by low Hb during crucial periods of development. PMID:22507306

  17. Gene cooption and convergent evolution of oxygen transport hemoglobins in jawed and jawless vertebrates

    PubMed Central

    Hoffmann, Federico G.; Opazo, Juan C.; Storz, Jay F.

    2010-01-01

    Natural selection often promotes evolutionary innovation by coopting preexisting genes for new functions, and this process may be greatly facilitated by gene duplication. Here we report an example of cooptive convergence where paralogous members of the globin gene superfamily independently evolved a specialized O2 transport function in the two deepest branches of the vertebrate family tree. Specifically, phylogenetic evidence demonstrates that erythroid-specific O2 transport hemoglobins evolved independently from different ancestral precursor proteins in jawed vertebrates (gnathostomes) and jawless fish (cyclostomes, represented by lamprey and hagfish). A comprehensive phylogenetic analysis of the vertebrate globin gene superfamily revealed that the erythroid hemoglobins of cyclostomes are orthologous to the cytoglobin protein of gnathostome vertebrates, a hexacoordinate globin that has no O2 transport function and that is predominantly expressed in fibroblasts and related cell types. The phylogeny reconstruction also revealed that vertebrate-specific globins are grouped into four main clades: (i) cyclostome hemoglobin + cytoglobin, (ii) myoglobin + globin E, (iii) globin Y, and (iv) the α- and β-chain hemoglobins of gnathostomes. In the hemoglobins of gnathostomes and cyclostomes, multisubunit quaternary structures provide the basis for cooperative O2 binding and allosteric regulation by coupling the effects of ligand binding at individual subunits with interactions between subunits. However, differences in numerous structural details belie their independent origins. This example of convergent evolution of protein function provides an impressive demonstration of the ability of natural selection to cobble together complex design solutions by tinkering with different variations of the same basic protein scaffold. PMID:20660759

  18. Selective Removal of Hemoglobin from Blood Using Hierarchical Copper Shells Anchored to Magnetic Nanoparticles

    PubMed Central

    Wang, Yaokun; Yan, Mingyang

    2017-01-01

    Hierarchical copper shells anchored on magnetic nanoparticles were designed and fabricated to selectively deplete hemoglobin from human blood by immobilized metal affinity chromatography. Briefly, CoFe2O4 nanoparticles coated with polyacrylic ac