Search results for "erythrocytes"
showing 10 items of 218 documents
Electron Microscopy of Human Erythrocyte Catalase: New Two-Dimensional Crystal Forms
1993
Abstract Using the mica-spreading "negative staining-carbon film" procedure, human erythrocyte catalase has been shown to create a number of different periodic or crystalline two-dimensional (2-D) arrays which differ in the arrangement of molecules in the repeating units and the lattice type. Digital image processing has been performed with a 2-D array which contains regularly arranged "undulating" rows of molecules and also with a 2-D crystal form, exhibiting pgg (p22 1 2 1 ) symmetry and lattice parameters of a = 12.7 nm, b = 44 nm, and γ= 92°. The data are compared with our previous analysis of a different human erythrocyte catalase 2-D crystal, and the effect of partial-depth negative s…
In vitro leishmanicidal activity of pyrazole-containing polyamine macrocycles which inhibit the Fe-SOD enzyme of Leishmania infantum and Leishmania b…
2014
The in vitro leishmanicidal activity and cytotoxicity of pyrazole-containing macrocyclic polyamines 1-4 was assayed on Leishmania infantum and Leishmania braziliensis species. Compounds 1-4 were more active and less toxic than glucantime and both infection rates and ultrastructural alterations confirmed that 1 and 2 were highly leishmanicidal and induced extensive parasite cell damage. Modifications in the excretion products of parasites treated with 1-3 were also consistent with substantial cytoplasm alterations. Compound 2 was highlighted as a potent inhibitor of Fe-SOD in both species, whereas its effect on human CuZn-SOD was poor. Molecular modelling suggested that 2 could deactivate Fe…
Formation, TEM study and 3D reconstruction of the human erythrocyte peroxiredoxin-2 dodecahedral higher-order assembly.
2004
The production of a higher-order assembly of peroxiredoxin-2 (Prx-2) from human erythrocytes has been achieved during specimen preparation on holey carbon support films, in the presence of ammonium molybdate and polyethylene glycol. TEM study suggested that this assembly is a regular dodecahedron, containing 12 Prx-2 decamers (Mr 2.62 MDa, external diameter approximately 20 nm). This interpretation has been supported by production of a approximately 1.6 nm 3D reconstruction from the negative stain TEM data, with automated docking of the available X-ray data of the Prx-2 decamer. Comparison with other known protein dodecahedral and viral icosahedral structures indicates that this arrangement…
Comparison of the decameric structure of peroxiredoxin-II by transmission electron microscopy and X-ray crystallography
2001
Abstract The decameric human erythrocyte protein torin is identical to the thiol-specific antioxidant protein-II (TSA-II), also termed peroxiredoxin-II (Prx-II). Single particle analysis from electron micrographs of Prx-II molecules homogeneously orientated across holes in the presence of a thin film of ammonium molybdate and trehalose has facilitated the production of a ≥20 A 3-D reconstruction by angular reconstitution that emphasises the D5 symmetry of the ring-like decamer. The X-ray structure for Prx-II was fitted into the transmission electron microscopic reconstruction by molecular replacement. The surface-rendered transmission electron microscopy (TEM) reconstruction correlates well…
Tetracycline-controlled transgenic targeting from the SCL locus directs conditional expression to erythrocytes, megakaryocytes, granulocytes, and c-k…
2006
The stem cell leukemia gene SCL, also known as TAL-1, encodes a basic helix-loop-helix transcription factor expressed in erythroid, myeloid, megakaryocytic, and hematopoietic stem cells. To be able to make use of the unique tissue-restricted and spatio-temporal expression pattern of the SCL gene, we have generated a knock-in mouse line containing the tTA-2S tetracycline transactivator under the control of SCL regulatory elements. Analysis of this mouse using different tetracycline-dependent reporter strains demonstrated that switchable transgene expression was restricted to erythrocytes, megakaryocytes, granulocytes, and, importantly, to the c-kit-expressing and lineage-negative cell fracti…
Nanoassemblies Based on Supramolecular Complexes of Nonionic Amphiphilic Cyclodextrin and Sorafenib as Effective Weapons to Kill Human HCC Cells
2015
Sorafenib (Sor), an effective chemiotherapeutic drug utilized against hepatocellular carcinoma (HOC), robustly interacts with nonionic amphiphilic cyclodextrin (aCD, SC6OH), forming, in aqueous solution, supramolecular complexes that behave as building blocks of highly water-dispersible colloidal nanoassemblies. SC6OH/Sor complex has been characterized by complementary spectroscopic techniques, such as UV-vis, steady-state fluorescence and anisotropy, resonance light scattering and H-1 NMR. The spectroscopic evidences and experiments carried out in the presence of an adamantane derivative, which competes with drug for CD cavity, agree with the entrapment of Sor in aCD, pointing out the role…
Untersuchungen über den Einfluß langkettiger fettsaurer Salze auf Erythrozyten
1969
Natrium-oleat und Olsaure haben spezifische morphologische und funktionelle Wirkungen auf menschliche Erythrozyten in vitro. Eine Erhohung der Konzentration dieser Substanzen im Blut fuhrt zu reversiblen stechapfelformigen Veranderungen der Erythrozytenform, zur Hemmung der Blutkorperchensenkungsgeschwindigkeit und zur Senkung der Strukturviskositat des Blutes. Weiterhin wird bei Konzentrationen bis 45 mg% die osmotische Resistenz der Erythrozyten verbessert. Erst hohe Konzentrationen an Na-oleat im Blut fuhren zur Hamolyse. Investigations on the Influence of Long Chain Fatty Acid Salts on Erythrocytes Sodium oleate and oleic acid have specific morphological and functional action on human e…
Pertuzumab monotherapy after trastuzumab-based treatment and subsequent reintroduction of trastuzumab: activity and tolerability in patients with adv…
2012
Purpose The combination of pertuzumab and trastuzumab resulted in a clinical benefit rate (CBR) of 50% in patients with human epidermal growth factor receptor 2 (HER2) –positive breast cancer whose disease progressed during prior trastuzumab-based therapy. To define whether this previously observed encouraging activity was a result of the combination of pertuzumab and trastuzumab or of pertuzumab alone, we recruited a third cohort of patients who received pertuzumab without trastuzumab. We then investigated the impact of reintroducing trastuzumab to patients whose disease progressed on pertuzumab monotherapy. Patients and Methods Twenty-nine patients with HER2-positive breast cancer whose d…
Der erythrocytäre Magnesiumstoffwechsel bei intakter und kälteinhibierter Glykolyse
1962
Continuation of glycolysis in human erythrocytes by incubation of heparinized whole blood at 37°C is followed by a decrease in the Mg-content of red cells. On inhibition of glycolysis by cold (4°C), the Mg-content of erythrocytes remains unaltered or, often, slightly increases. These actions are in clear contrast to the behaviour of potassium ions under the same conditions.
Oxygen exchange in the erythrocyte
1969
Es wird eine Ubersicht uber die mathematischen und experimentellen Aspekte des O2-Austausches im Erythrozyten gegeben. Der Gesamtprozess kann als eine Sauerstoffdiffusion mit gekoppelter Hamoglobin-Sauerstoff-Reaktion beschrieben werden. Fur die mathematische Analyse muss also die partielle Differentialgleichung der Diffusion durch ein Gleichungssystem erweitert werden, das dem chemischen Reaktionsablauf Rechnung tragt. Voraussetzung hierfur ist die Aufstellung eines Modells zur molekularen Interpretation der O2-Bindungskurve. Die vereinfachten Differentialgleichungen fur Diffusion und Reaktion lassen sich unter Beachtung der Rand- und Anfangsbedingungen nur naherungsweise integrieren.