scholarly journals Structural changes introduced by cholesterol and melatonin to the model membranes mimicking preclinical conformational diseases

2020 ◽  
Vol 39 (02) ◽  
pp. 135-144
Author(s):  
Tatiana Murugova ◽  
Oleksandr Ivankov ◽  
Elena Ermakova ◽  
Tomáš Kondela ◽  
Pavol Hrubovčák ◽  
...  
Keyword(s):  
Structural Changes ◽  
Model Membranes ◽  
Conformational Diseases

Influence of Dodecyltrimethylammonium Halides on Interaction of Phenyltin Compounds with Model Membranes

2001 ◽  
Vol 56 (7-8) ◽  
pp. 623-628
Author(s):  
Bożenna Różycka-Roszak ◽  
Hanna Pruchnik
Keyword(s):  
Phase Formation ◽  
Nmr Spectra ◽  
Structural Changes ◽  
Hexagonal Phase ◽  
Model Membranes ◽  
Phase Behaviour ◽  
Dodecyltrimethylammonium Bromide ◽  
H Nmr ◽  
Dodecyltrimethylammonium Chloride ◽  
Triphenyltin Chloride

The effects were studied of dodecyltrimethylammonium chloride (DTAC), dodecyltrimethylammonium bromide (DTAB) and dodecyltrimethylammonium iodide (DTAI) on thermo­tropic phase behaviour of phosphatidylcholine bilayers, as well as on 1H NMR and 31P NMR spectra, in the presence of diphenyltin dichloride (DPhT) and triphenyltin chloride (TPhT). The obtained results indicate that in the presence of the surfactant studied the interaction of phenyltin compounds with model membranes was changed and the changes depended on the kind of the counterion. The surfactants studied (especially DTAC) decrease the ability of phenyltin compounds to induce structural changes in the bilayer. It is suggested that DTAB, and especially DTAC, prevent DPhT induced interdigitated phase formation as well as formation of an inverted hexagonal phase (HII) in the case of TPhT/DPPC liposomes

scholarly journals Structural Changes in Lipid Model Membranes Induced by the Fungal Peptide Toxin Ece1-III

2016 ◽  
Vol 110 (3) ◽  
pp. 29a
Author(s):  
Julia Wernecke ◽  
Laura Paulowski ◽  
Bernhard Hube ◽  
Oliver H. Seeck ◽  
Thomas Gutsmann
Keyword(s):  
Structural Changes ◽  
Model Membranes ◽  
Peptide Toxin

scholarly journals In situ Monitoring of Structural Changes in Model Membranes upon Cholesterol Depletion via X-ray Diffraction

2011 ◽  
Vol 100 (3) ◽  
pp. 625a
Author(s):  
Kathleen D. Cao ◽  
Luka Pocivavsek ◽  
Niels Holten-Andersen ◽  
Stephanie A. Harmon ◽  
Mati Meron ◽  
...  
Keyword(s):  
Structural Changes ◽  
Model Membranes ◽  
In Situ Monitoring ◽  
Cholesterol Depletion ◽  
X Ray Diffraction ◽  
X Ray

Interactions in the model membranes mimicking preclinical conformational diseases

2020 ◽  
pp. 185-214 ◽  
Author(s):  
Oleksandr I. Ivankov ◽  
Elena V. Ermakova ◽  
Tatiana N. Murugova ◽  
Dina R. Badreeva ◽  
Ermuhammad Dushanov ◽  
...  
Keyword(s):  
Model Membranes ◽  
Conformational Diseases

Fine Structural Changes in the Microvasculature of the Mouse Pinna: Aging and Radiation Injury

1974 ◽  
Vol 32 ◽  
pp. 54-55
Author(s):  
S. Phyllis Steamer ◽  
Rosemarie L. Devine
Keyword(s):  
Structural Changes ◽  
Radiation Treatment ◽  
Arterial Stenosis ◽  
Ultrastructural Changes ◽  
Vascular Effects ◽  
Microvascular Changes ◽  
Surrounding Connective Tissue ◽  
Fission Neutrons ◽  
Total Body

The importance of radiation damage to the skin and its vasculature was recognized by the early radiologists. In more recent studies, vascular effects were shown to involve the endothelium as well as the surrounding connective tissue. Microvascular changes in the mouse pinna were studied in vivo and recorded photographically over a period of 12-18 months. Radiation treatment at 110 days of age was total body exposure to either 240 rad fission neutrons or 855 rad 60Co gamma rays. After in vivo observations in control and irradiated mice, animals were sacrificed for examination of changes in vascular fine structure. Vessels were selected from regions of specific interest that had been identified on photomicrographs. Prominent ultrastructural changes can be attributed to aging as well as to radiation treatment. Of principal concern were determinations of ultrastructural changes associated with venous dilatations, segmental arterial stenosis and tortuosities of both veins and arteries, effects that had been identified on the basis of light microscopic observations. Tortuosities and irregularly dilated vein segments were related to both aging and radiation changes but arterial stenosis was observed only in irradiated animals.

Evaluation of single-electron movies of glutamine synthetase molecules

1983 ◽  
Vol 41 ◽  
pp. 280-281
Author(s):  
W. Kunath ◽  
E. Zeitler ◽  
M. Kessel
Keyword(s):  
Electron Microscope ◽  
Glutamine Synthetase ◽  
Electron Irradiation ◽  
Structural Damage ◽  
Structural Changes ◽  
Single Electron ◽  
Continuous Series ◽  
Digital Recording ◽  
Recording Device ◽  
Low Exposure

The features of digital recording of a continuous series (movie) of singleelectron TV frames are reported. The technique is used to investigate structural changes in negatively stained glutamine synthetase molecules (GS) during electron irradiation and, as an ultimate goal, to look for the molecules' “undamaged” structure, say, after a 1 e/Å2 dose.The TV frame of fig. la shows an image of 5 glutamine synthetase molecules exposed to 1/150 e/Å2. Every single electron is recorded as a unit signal in a 256 ×256 field. The extremely low exposure of a single TV frame as dictated by the single-electron recording device including the electron microscope requires accumulation of 150 TV frames into one frame (fig. lb) thus achieving a reasonable compromise between the conflicting aspects of exposure time per frame of 3 sec. vs. object drift of less than 1 Å, and exposure per frame of 1 e/Å2 vs. rate of structural damage.

Fine Structural Changes in the Adenohypophyses of Rats Following Destruction of the Pituitary Stalk

1977 ◽  
Vol 35 ◽  
pp. 496-497
Author(s):  
K. Kovacs ◽  
E. Horvath ◽  
J. M. Bilbao ◽  
F. A. Laszlo ◽  
I. Domokos
Keyword(s):  
Structural Changes ◽  
Tissue Injury ◽  
Anterior Lobe ◽  
Uranyl Acetate ◽  
Male Rats ◽  
Pituitary Stalk ◽  
Sequence Of Events ◽  
Pituitary Glands ◽  
Electrolytic Lesions ◽  
Ultrathin Sections

Electrolytic lesions of the pituitary stalk in rats interrupt adenohypophysial blood flow and result in massive infarction of the anterior lobe. In order to obtain a deeper insight into the morphogenesis of tissue injury and to reveal the sequence of events, a fine structural investigation was undertaken on adenohypophyses of rats at various intervals following destruction of the pituitary stalk.The pituitary stalk was destroyed electrolytically, with a Horsley-Clarke apparatus on 27 male rats of the R-Amsterdam strain, weighing 180-200 g. Thirty minutes, 1,2,4,6 and 24 hours after surgery the animals were perfused with a glutaraldehyde-formalin solution. The skulls were then opened and the pituitary glands removed. The anterior lobes were fixed in glutaraldehyde-formalin solution, postfixed in osmium tetroxide and embedded in Durcupan. Ultrathin sections were stained with uranyl acetate and lead citrate and investigated with a Philips 300 electron microscope.

Membrane Changes in Polymorphonuclear Leukocytes During Ionophore (A23187) - Induced Lysosomal Release

1977 ◽  
Vol 35 ◽  
pp. 482-483
Author(s):  
P.L. Moore ◽  
P.L. Sannes ◽  
H.L. Bank ◽  
S.S. Spicer
Keyword(s):  
Structural Changes ◽  
Calcium Release ◽  
Clear Understanding ◽  
Ionophore A23187 ◽  
Enzyme Release ◽  
Extracellular Medium ◽  
Pmn Leukocytes ◽  
Intracellular Ion Concentrations ◽  
Membrane Changes ◽  
Pmn Leukocyte

It is thought that calcium and/or magnesium may play important roles in polymorphonuclear (PMN) leukocyte functions such as chemotaxis, adhesion and phagocytosis. Yet, a clear understanding of the biological roles of these ions has awaited the development of techniques which permit a selective alteration of intracellular ion concentrations. Recently, treatment of cells with the ionophore A23187 has been used to alter intracellular divalent cation concentrations. This ionophore is a lipid soluble antibiotic produced by Streptomyces chartreusensis that complexes with both calcium and magnesium (3) and is believed to carry these ions across biological membranes (4). Biochemical investigations of human PMN leukocytes demonstrate that cells treated with A23187 and extracellular calcium release their lysosomal enzymes into the extracellular medium without rupturing and releasing their soluble cytoplasmic enzymes (5,6). The aim of the present study and and a companion report (7) was to investigate the structural changes that occur in leukocytes during ionophore-induced lysosomal enzyme release.

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