Search results for "Dextran"
showing 10 items of 133 documents
Biodegradable hydrogels obtained by photocrosslinking of dextran and polyaspartamide derivatives
2003
The functionalization of dextran with glycidyl methacrylate (GMA) leads to the formation of a derivative that generates hydrogels for irradiation at 365nm. The effects of various polymer concentrations and irradiation times on the yield and the properties of the obtained hydrogels are reported. The networks have been characterized by FT-IR spectra, dimensional analysis and swelling measurements carried out at different pH values. In vitro studies suggest that all samples undergo a partial chemical hydrolysis, whereas the incubation with dextranases causes a total degradation whose rate depends on the degree of crosslinking. In addition, aqueous solutions of functionalized dextran have been …
Pharmakokinetik und Dosierung von Dextran 40 in Abh�ngigkeit von der Nierenfunktion
1974
36 Patienten mit unterschiedlicher Nierenfunktion (GFR zwischen 0,5–142 ml/min) erhielten 500 ml 10%iges Dextran 40 (Rheomacrodex®). Dabei ergab sich ein relatives Verteilungsvolumen von 10,2±2,2 1/100 kg. Die Eliminationshalbwertzeiten von Dextran 40 stehen mit der Nierenfunktion (51 Cr-EDTA-Clearance) in einem Zusammenhang, der sich rechnerisch am besten durch eine Potenzfunktion darstellen last. Patienten mit normaler Nierenfunktion (GFR uber 90 ml/min) haben eine Eliminationshalbwertzeit von 573±138 min und eine 12 Std-Recovery im Urin von 48%. Ein Glomerulusfiltrat unter 10 ml/min fuhrt dagegen zur Verlangerung der Halbwertzeit auf das Funffache (Dextran 40-HWZ=2591±1022 min) und zum R…
Dosierung und Elimination von Dextran 40 bei H�modialysepatienten
1975
Bei 24 Hamodialysepatienten wurden nach einmaliger und wiederholter Gabe von Dextran 40 (Rheomacrodex®) die Dextranspiegel im Serum bestimmt und daraus die Eliminationshalbwertzeiten errechnet. Diese betrugen bei Heimdialysepatienten 2237±447 min, bei Zentrumsdialysepatienten 4283±810 min und waren damit gegenuber nierengesunden Patienten (HWZ=573±183 min) auf das Funf- bzw. Zehnfache verlangert. Die Unterschiede zwischen Heimdialyse- und Zentrumsdialysepatienten erklaren sich durch die bessere Nierenrestfunktion der ersteren. Wahrend der Hamodialyse kam es zu keinem Abfall der Dextranspiegel i.S. Weiterhin zeigte sich, das die exponentielle Elimination von Dextran 40 uber einen Beobachtung…
Digestive vacuole of Plasmodium falciparum released during erythrocyte rupture dually activates complement and coagulation.
2012
Abstract Severe Plasmodium falciparum malaria evolves through the interplay among capillary sequestration of parasitized erythrocytes, deregulated inflammatory responses, and hemostasis dysfunction. After rupture, each parasitized erythrocyte releases not only infective merozoites, but also the digestive vacuole (DV), a membrane-bounded organelle containing the malaria pigment hemozoin. In the present study, we report that the intact organelle, but not isolated hemozoin, dually activates the alternative complement and the intrinsic clotting pathway. Procoagulant activity is destroyed by phospholipase C treatment, indicating a critical role of phospholipid head groups exposed at the DV surfa…
Isoproterenol inhibits fluid-phase endocytosis from early to late endosomes
1999
We have shown recently that isoproterenol affects both the cellular location and the morphology of late endosomes in a pH-dependent manner [Marjomäki et al., Eur. J. Cell Biol. 65, 1-13 (1994)]. In this study, using fluorescence and quantitative electron microscopy, we wanted to examine further what is the fate of internalized markers during their translocation from early to late endosomes under isoproterenol treatment. Fluorescein dextran internalized for 30 min (10-min pulse followed by a 20-min chase) showed accumulation in the cellular periphery during isoproterenol treatment in contrast to the control cells, which accumulated dextran in the perinuclear region. Quantitative electron mic…
Size-isolation of superparamagnetic iron oxide nanoparticles improves MRI, MPI and hyperthermia performance.
2020
Journal of nanobiotechnology 18, 22 (2020). doi:10.1186/s12951-020-0580-1
Effects of Dextran Sulfate 500 on Cell-Mediated Resistance to Infection with Listeria monocytogenes in Mice.
1974
Injection of dextran sulfate 500 caused loss of antibacterial resistance. Mice became more susceptible to an infection with Listeria monocytogenes and were unable to develop antilisterial immunity after both active and passive immunization with passively administered spleen cells from Listeria -immune donors. Indirect evidence suggests that the phagocytic component of cell-mediated resistance to bacterial infection is the site of attack of dextran sulfate.
Double stimuli-responsive polysaccharide block copolymers as green macrosurfactants for near-infrared photodynamic therapy
2019
The NIR absorbing photosensitizer phthalocyanine zinc (PC(Zn)) was stabilized in aqueous media as water-dispersible nanoparticles with a reduction- and pH-responsive full polysaccharide block copolymer. A cellular uptake and also photo switchable intracellular activity of the cargo upon irradiation at wavelengths in the near infrared region were shown. The block copolymer was synthesized by applying a copper-free click strategy based on a thiol exchange reaction, creating an amphiphilic double-stimuli-responsive mixed disulfide. The dual-sensitive polysaccharide micelles represent a non-toxic and biodegradable green macrosurfactant for the delivery of phthalocyanine zinc. By encapsulation i…
Morphological Changes Induced by Dextran Sulfate 500 in Mononuclear Phagocytes of Listeria-Infected Mice
1974
Morphological changes involving mononuclear phagocytes in Listeria -infected mice after treatment with dextran sulfate 500 were investigated. Mononuclear phagocytes in livers and spleens, both circulating monocytes and fixed macrophages, showed uptake of electron-dense material. Mononuclear phagocyte changes were most pronounced within granulomatous lesions, where many phagocytes showed large membrane-bound inclusions and extensive cellular damage. It is concluded that dextran sulfate 500 selectively damages mononuclear phagocytes and that, in listerial infection, dextran sulfate 500 renders mononuclear phagocytes unable to express cellular resistance.
Dextrans produced by lactic acid bacteria exhibit antiviral and immunomodulatory activity against salmonid viruses
2015
36 p.-7 fig.-1 tab.-1 fig. supl.