The Experts below are selected from a list of 198 Experts worldwide ranked by ideXlab platform

Jorg Kreuter - One of the best experts on this subject based on the ideXlab platform.

  • significant transport of doxorubicin into the Brain with polysorbate 80 coated nanoparticles
    Pharmaceutical Research, 1999
    Co-Authors: A E Gulyaev, Svetlana Gelperina, I N Skidan, Arkady S Antropov, Gregory Ya Kivman, Jorg Kreuter
    Abstract:

    Purpose. To investigate the possibility of delivering of anticancer drugs into the Brain using colloidal carriers (nanoparticles). Methods. Rats obtained 5 mg/kg of doxorubicin by i v. injection in form of 4 preparations : 1. a simple solution in saline, 2. a simple solution in polysorbate 80 1% in saline, 3. bound to poly (butyl cyanoacrylate) nanoparticles, and 4. bound to poly(butyl cyanoacrylate) nanoparticles overcoated with 1% polysorbate 80 (Tween® 80). After sacrifice of the animals after 10 min, 1, 2, 4, 6, and 8 hours, the doxorubicin concentrations in plasma, liver, spleen, lungs, kidneys, heart and Brain were determined after extraction by HPLC. Results. No significant difference in the body distribution was observed between the two solution formulations. The two nanoparticle formulations very significantly decreased the heart concentrations. High Brain concentrations of doxorubicin (>6 μg/g) were achieved with the nanoparticles overcoated with polysorbate 80 between 2 and 4 hours. The Brain concentrations observed with the other three preparations were always below the detection limit (< 0.1 |μg/g). Conclusions. The present study demonstrates that the Brain concentration of systemically administered doxorubicin can be enhanced over 60-fold by binding to biodegradable poly(butyl cyanoacrylate) nanoparticles, overcoated with the nonionic surfactant polysorbate 80. It is highly probable that coated particles reached the Brain intact and released the drug after endocytosis by the Brain Blood Vessel endothelial cells.

  • passage of peptides through the Blood Brain barrier with colloidal polymer particles nanoparticles
    Brain Research, 1995
    Co-Authors: Jorg Kreuter, Renad N Alyautdin, Dimitri A Kharkevich, Alexei A Ivanov
    Abstract:

    Abstract Transport of the hexapeptide dalargin across the Blood-Brain barrier was accomplished using a nanoparticle formulation. The formulation consisted of dalargin bound to poly(butyl cyanoacrylate) nanoparticles by sorption, coated with polysorbate 80. Intravenous injection of this formulation to mice resulted in an anlgesic effect. All controls, including a simple mixture of the three components (drugs, nanoparticles, and surfactant) mixed directly before i.v. injection, exhibited no effect. Analgesia was also prevented by pretreatment with naloxone. Fluorescent and electron microscopic studies indicated that the passage of the particle-bound drug occurred by phagocytic uptake of the polysorbate 80-coated nanoparticles by the Brain Blood Vessel endothelial cells.

Robert A. Gross - One of the best experts on this subject based on the ideXlab platform.

  • Mouse Brain KaleidoscopeAuthor ResponseEditor’s Note
    Neurology, 2013
    Co-Authors: Steven R. Brenner, Fernando Calamante, Robert A. Gross
    Abstract:

    Editors' Note: Drs. Brenner, Calamante, and Gross, Neurology ® Editor-in-Chief, discuss the ethical implications of the artistic interpretation of animal research. Teive and colleagues describe their experience with a patient with lipoid proteinosis to further stress the susceptibility of Brain Blood Vessel to rupture in this disease. Chafic Karam, MD, and Robert C. Griggs, MD # {#article-title-2} While this image is beautiful,1 it seems to have gone beyond the intended purpose of the original research on …

Sherwin Wilk - One of the best experts on this subject based on the ideXlab platform.

  • Localization of immunoreactive glutamyl aminopeptidase in rat Brain. II. Distribution and correlation with angiotensin II.
    Brain research, 1993
    Co-Authors: Dennis P. Healy, Sherwin Wilk
    Abstract:

    Abstract Glutamyl aminopeptidase (EAP, EC 3.4.11.7) selectively hydrolyzes N-terminal glutamyl and aspartyl residues from oligopeptides and is present in the Brain. (Asp1)Angiotensin II (Ang II) is a substrate for EAP, and increasing evidence suggests that des(Asp1)angiotensin II (Ang III) is an active angiotensin peptide in the Brain. To determine whether a relationship exists between EAP and Ang II/III in rat Brain, we compared their immunocytochemical distributions. EAP-like immunoreactivity was localized primarily to the adventitial surface of cerebral microVessels throughout the foreBrain. Endothelial cells, neurons and glial cells were not labeled. The immunocytochemical staining of microVessel adventitium with EAP antiserum was suggestive of labeling of perivascular pericytes since intravenous horseradish peroxidase resulted in a similar adventitial pattern of staining, in addition to pericyte cell bodies. EAP immunoreactivity was highest within circumventricular organs, areas known to contain high levels of Ang II receptors. Positively stained EAP microVessels were also concentrated in areas containing Ang II/III immunoreactive neurons or nerve terminals, including the hypothalamic paraventricular nucleus and the median eminence. The immunocytochemical localization of EAP suggests that it may be involved in a wide variety of functions within the Brain, including: (i) metabolism of circulating peptides in Brain areas devoid of a Blood-Brain barrier, (ii) metabolism of circulating peptides as a component of the Blood-Brain barrier, (iii) metabolism of intravascularly synthesized peptides, (iv) metabolism of hypothalamic peptides released into the portal circulation, (v) metabolism/conversion of neuronally released Ang II to Ang III in the interstitial space, and (vi) metabolism of neuronally released neuropeptides with vasoactive properties. In this latter capacity, EAP may play a role as a component of a Brain-Blood Vessel barrier to neuropeptides that could alter regional Blood flow or vascular permeability.

Grant W. Anderson - One of the best experts on this subject based on the ideXlab platform.

  • Fetal and neonatal iron deficiency but not copper deficiency increases vascular complexity in the developing rat Brain.
    Nutritional neuroscience, 2015
    Co-Authors: Thomas W. Bastian, Stephanie Santarriaga, Thu An Nguyen, Joseph R. Prohaska, Michael K. Georgieff, Grant W. Anderson
    Abstract:

    Objectives: Anemia caused by nutritional deficiencies, such as iron and copper deficiencies, is a global health problem. Iron and copper deficiencies have their most profound effect on the developing fetus/infant, leading to Brain development deficits and poor cognitive outcomes. Tissue iron depletion or chronic anemia can induce cellular hypoxic signaling. In mice, chronic hypoxia induces a compensatory increase in Brain Blood Vessel outgrowth. We hypothesized that developmental anemia, due to iron or copper deficiencies, induces angiogenesis/vasculogenesis in the neonatal Brain.Methods: To test our hypothesis, three independent experiments were performed where pregnant rats were fed iron- or copper-deficient diets from gestational day 2 through mid-lactation. Effects on the neonatal Brain vasculature were determined using quantitative real-time polymerase chain reaction to assess mRNA levels of angiogenesis/vasculogenesis-associated genes and GLUT1 immunohistochemistry to assess Brain Blood Vessel densi...

A. Martin Gerdes - One of the best experts on this subject based on the ideXlab platform.