Search results for "Transferrin"
showing 10 items of 101 documents
A Novel 68Ga-Labeled Pteroic Acid-Based PET Tracer for Tumor Imaging via the Folate Receptor
2012
The folate receptor (FR) is a very attractive target in oncological imaging as it is overexpressed by a variety of cancer types, whereas the expression in healthy tissue is very limited. The synthesis of regioisomeric pure folic acid derivatives normally requires a regioselective approach and does not allow the use of native folic acid (FA). As the pharmacophore of FA is assumed to be pteroic acid, its use without the glutamic acid moiety may enable the possibility to considerably simplify the synthesis of a positron emission tomography (PET) tracer for FR imaging. In this work, DO3A-EA-Pte was successfully synthesized and labeled with 68Ga. It is stable for up to 3 h in PBS and against tra…
Investigations on the geographical variability of the human transferrins.
1971
On the basis of own and from the widely scattered literature compiled materials the geographical distribution of the transferrin alleles is discussed. They reveal a characteristic distribution pattern, as the slow Tf variants produced by TfD alleles are obviously more frequent in tropical than in non-tropical populations. Considering similar results in cattle and its interpretation by Ashton (1958, 1965), it is hypothesized, that the relatively high TfΓ frequencies in tropical biotops might be a selective adaptation to their special climatic conditions. In this connection an association between slowly moving transferrin proteins in man and tolerance to hotter climates — as could be found in…
Super-high-speed liquid chromatography of proteins and peptides on non-porous Micra NPS-RP packings
1999
Abstract The new generation of non-porous silica RP packings commercially available from Micra Scientific was tested for separations of peptides and proteins by means of the gradient HPLC. Extremely high-speed separations were achieved using conventional chromatographic equipment: six proteins could be completely separated within six seconds. Tryptic digest peptides could be resolved in more then 40 components within 2–3 min. The effect of the experimental parameters such as temperature, flow rate etc. was investigated.
Quantitative Bestimmungen der Bluteiwei�e, speziell des Transferrins und des Haptoglobins, bei der Porphyria cutanea tarda
1964
Es wurden quantitative Bestimmungen des Transferrins, Haptoglobins und des Eisens an 10 Patienten mit Porphyria cutanea tarda durchgefuhrt. Dabei konnte eine statistisch gesicherte Verminderung des Transferrins und Erhohung des Eisenspiegels im Serum bei P.c.t.-Kranken gegenuber gesunden Kontrollpersonen festgestellt werden. Es liegt daher eine relativ gesattigte Eisenbindungskapazitat vor, deren Bedeutung fur die Pathogenese der P.c.t. diskutiert wird.
Novel host-specific iron acquisition system in the zoonotic pathogenVibrio vulnificus
2015
Summary Vibrio vulnificus is a marine bacterium associated with human and fish (mainly farmed eels) diseases globally known as vibriosis. The ability to infect and overcome eel innate immunity relies on a virulence plasmid (pVvbt2) specific for biotype 2 (Bt2) strains. In the present study, we demonstrated that pVvbt2 encodes a host-specific iron acquisition system that depends on an outer membrane receptor for eel transferrin called Vep20. The inactivation of vep20 did not affect either bacterial growth in human plasma or virulence for mice, while bacterial growth in eel blood/plasma was abolished and virulence for eels was significantly impaired. Furthermore, vep20 is an iron-regulated ge…
Studies towards the development of lipophilic bifunctional N3S3 chelators for 68Ga
2010
Abstract The present study is concerned with a concept of charge-neutral, lipophilic, macrocyclic bifunctional chelators, suitable for the introduction of a gallium-68 label into small molecules. The synthesis of a novel bifunctional N3S3-type chelator, derived from 1,4,7-triazacyclononane, initial 68Ga-radiolabelling and the determination of stability and calculated lipophilicity of the compound are described. The 68Ga-labelled chelate was obtained in a maximum radiochemical yield of 93±5% after a reaction time of 2 min. It remained intact over 3 h in a DTPA-challenge and a transferrin challenge experiment, indicating sufficient stability for PET studies.
Aceruloplasminemia: a case report
2008
Hereditary aceruloplasminemia is a rare autosomal recessive disease, firstly identified by Miyajima et al. in Japan in 1987 [1]. The disease is caused by the absence of an a2glycoprotein, the ceruloplasmin (Cp), a copper-containing ferroxidase, mainly synthesized in hepatocytes and widely expressed, including the central nervous system, which catalyses the oxidation of ferrous to ferric iron, a change required for release of iron to plasma transferrin [2]. It is hypothesized that in reticuloendothelial (RE) cells and hepatocytes Cp cooperates to export iron with the iron exporter protein ferroportin 1 (FPN1) [3]. As a consequence, Cp deficiency results in iron deposition in the liver, pancr…
Iron deficiency testing and treatment in heart failure: the eyes are useless when the mind is blind
2021
Definition, clinical implications, and rate of iron deficiency assessment and treatment in the Swedish Heart Failure Registry. FCM, ferric carboxymaltose; HF, heart failue; ID, iron deficiency; TSAT, transferrin sauration.
Genetische Hämochromatose und das HFE-Gen: von der Molekulargenetik zur klinischen Diagnostik
2000
More than 90% of patients with genetic hemochromatosis carry a characteristic mutation in the HFE-gene (C282Y). HFE modulates the iron uptake by the transferrin receptor. Duodenal crypt cells of HFE-knockout mice show low intracellular iron concentrations which lead to an upregulation of the divalent metal transporter and enhanced iron uptake by duodenal enterocytes. Heterozygosity for the C282Y mutation appears to alter the course of other liver diseases like porphyria cutanea tarda and nonalcoholic steatohepatitis.
Regulation of the Transferrin Receptor Recycling in Hepatitis C Virus-Replicating Cells
2020
After binding of its ligand transferrin, the transferrin receptor (TfR) is internalized via early endosomes. Ligand and receptor can be recycled. α-Taxilin was identified as an essential factor for TfR recycling. Apart from its role for iron uptake, TfR is a coreceptor for hepatitis C virus (HCV) infection. In HCV-replicating cells, the amount of a-taxilin is decreased. This study aims to investigate the effect of decreased α-taxilin levels in HCV-replicating cells on recycling of TfR, its amount on the cell surface, on iron uptake, and the impact of a disturbed TfR recycling on HCV superinfection exclusion. TfR amount and localization were determined by CLSM and surface biotinylation. α-ta…