scholarly journals Partitioning of a Hybrid Lipid in Domains of Saturated and Unsaturated Lipids in a Model Cellular Membrane

ACS Omega ◽  
2021 ◽  
Author(s):  
Prashant Hitaishi ◽  
Priya Mandal ◽  
Sajal K. Ghosh
Keyword(s):  
Cellular Membrane ◽  
Unsaturated Lipids

Cytochemical analysis of mast cell granules after poly-dl-lysine action

1978 ◽  
Vol 36 (2) ◽  
pp. 278-279
Author(s):  
R. Courtoy ◽  
L.J. Simar ◽  
J. Christophe
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Chemical Compounds ◽  
Cellular Membrane ◽  
Thin Sections ◽  
Organic Bases ◽  
Ferric Thiocyanate ◽  
Cytochemical Analysis ◽  
Mast Cell Granule ◽  
Amine Liberation

Several chemical compounds induce amine liberation from mast cells but do not necessarily provoque the granule expulsion. For example, poly-dl-lysine induces modifications of the cellular membrane permeability which promotes ion exchange at the level of mast cell granules. Few of them are expulsed but the majority remains in the cytoplasm and appears less dense to the electrons. A cytochemical analysis has been performed to determine the composition of these granules after the polylysine action.We have previously reported that it was possible to demonstrate polyanions on epon thin sections using a cetylpyridinium ferric thiocyanate method. Organic bases are selectively stained with cobalt thiocyanate and the sulfhydryle groups are characterized with a silver methenamine reaction. These techniques permit to reveal the mast cell granule constituents, i.e. heparin, biogenic amines and basic proteins.

The Effect of Mitomycin C on Platelet Aggregation and Adenosine 3′, 5′-Monophosphate Metabolism

1978 ◽  
Vol 39 (01) ◽  
pp. 177-185 ◽  
Author(s):  
Shuichi Hashimoto ◽  
Sachiko Shibata ◽  
Bonro Kobayashi
Keyword(s):  
Platelet Aggregation ◽  
Cyclic Amp ◽  
Mitomycin C ◽  
Blood Platelets ◽  
Adenosine Diphosphate ◽  
Cellular Membrane ◽  
Adenyl Cyclase ◽  
Cyclic Amp Phosphodiesterase ◽  
Membrane Structure And Function ◽  
And Function

SummaryThe effect of Mitomycin C on aggregation, adenosine 3′, 5′-monophosphate (cyclic AMP) metabolism and reactions induced by thrombin was studied in rabbit platelets. Mitomycin C inhibited the platelet aggregation induced by adenosine diphosphate or thrombin. The level of radioactive cyclic AMP derived from 8-14C adenine or 8-14C adenosine increased after incubating intact platelets with Mitomycin G. Formation of radioactive adenosine triphosphate also increased though mitochondrial oxidation was not stimulated. Similar effect was observed also in rabbit liver. Mitomycin C failed to stimulate platelet adenyl cyclase but inhibited cyclic AMP phosphodiesterase in the absence of theophylline. In the platelets preincubated with Mitomycin C, thrombin-induced inhibition of adenyl cyclase, stimulation of membrane-bound cyclic AMP phosphodiesterase, and release of 250,000 dalton protein from platelet membranes were prevented. These results suggest that Mitomycin C will affect cellular membrane structure and function, and this extranuclear effect of Mitomycin C will lead to inhibition of aggregation in blood platelets.

Daunorubicin and Platelet Function

1981 ◽  
Vol 45 (01) ◽  
pp. 038-042 ◽  
Author(s):  
M E Pogliani ◽  
R Fantasia ◽  
G Lambertenghi-Deliliers ◽  
E Cofrancesco
Keyword(s):  
Electron Microscope ◽  
Cellular Membrane ◽  
Hemorrhagic Diathesis ◽  
Clot Retraction ◽  
Freezing And Thawing ◽  
Platelet Factor ◽  
High Doses ◽  
Very High ◽  
Platelet Functions

SummaryThe influence of Daunorubicin on some platelet functions in vitro was investigated, using different concentrations of the drug (0.01-0.02-0.04 μg/ml). Daunorubicin was shown to inhibit Collagen and Thrombin induced platelet aggregation and the intensity of inhibition depended on both drug concentration and the time of preincubation.Daunorubicin was also shown to inhibit the release reaction, the platelet prostaglandin pathway and the availability platelet factor 3; the drug at concentrations for clinical use does not damage the platelet membrane, as is the case with the freezing and thawing test, in platelet uptake of 14C-serotonin and as confirmed by the electron microscope. When very high doses (0.16 mg) of Daunorubicin are used, lysis of the platelets can be observed and this is confirmed under the electron microscope by the presence of empty platelets with fractures at the level of the cytoplasmic membrane.Finally, Daunorubicin causes irreversible inhibition of reptilase clot-retraction, even if this is less severe than with Vincristine. Working with gel-filtered platelets, it would appear that the inhibition exercised by the drug on platelet reactions is not caused through modifications in Ca++ metabolism.The authors suggest that Daunorubicin, at the dosages used clinically, induces in vitro thrombocytopathy without damaging the cellular membrane as confirmed by the electron microscope.This impairment of platelet functions could play a part in hemorrhagic diathesis observed during Daunorubicin therapy.

EFFECT OF CELLULAR MEMBRANE RESISTIVITY INHOMOGENEITY ON THE THERMAL NOISE-LIMIT

2015 ◽  
Vol 11 (3) ◽  
pp. 3171-3183
Author(s):  
Gyula Vincze
Keyword(s):  
Field Strength ◽  
Thermal Noise ◽  
Cellular Membrane ◽  
Thermal Limit ◽  
Low Frequencies ◽  
Membrane Resistivity ◽  
Noise Limit ◽  
The Asymmetry ◽  
Characteristic Field

Our objective is to generalize the Weaver-Astumian (WA) and Kaune (KA) models of thermal noise limit to the case ofcellular membrane resistivity asymmetry. The asymmetry of resistivity causes different effects in the two models. In the KAmodel, asymmetry decreases the characteristic field strength of the thermal limit over and increases it below the breakingfrequency (10  m), while asymmetry decreases the spectral field strength of the thermal noise limit at all frequencies.We show that asymmetry does not change the character of the models, showing the absence of thermal noise limit at highand low frequencies in WA and KA models, respectively.

Visible-Light Activated [2+2] Photocycloaddition Reaction Enabled Identification of Carbon-Carbon Double Bonds Position Isomerism in Structural Lipidomics

2020 ◽  
Author(s):  
Guifang Feng ◽  
Yanhong Hao ◽  
Liang Wu ◽  
Suming Chen
Keyword(s):  
Visible Light ◽  
Uv Light ◽  
Practical Importance ◽  
Side Reactions ◽  
Potential Health ◽  
Fundamental Interest ◽  
Unsaturated Lipids ◽  
Health Damage ◽  
Global Identification ◽  
Polyunsaturated Lipids

The photocycloaddition of olefins with carbonyls is of fundamental interest and practical importance in C=C bond location in unsaturated lipids. However, the traditional UV light activated [2+2] photocycloaddition reaction suffers side reactions and potential health damage. Here, we reported the first example of visible-light activated [2+2] photocycloaddition of anthraquinone with unsaturated lipids. This reaction showed great capability for locating the C=C bonds in various kinds of monounsaturated and polyunsaturated lipids by combining with tandem mass spectrometry (MS), such as fatty acids, phospholipids and glycerides. Based on this developed reaction, a workflow with liquid chromatography tandem MS method was developed for the global identification of unsaturated lipids in human serum, and 86 of monounsaturated and complicated polyunsaturated lipids were identified with definitive positions of C=C bonds. This approach provides new insights both on the photocycloaddition reactions and the structural lipidomics.

scholarly journals Recent Developments in Seafood Packaging Technologies

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 940
Author(s):  
Michael G. Kontominas ◽  
Anastasia V. Badeka ◽  
Ioanna S. Kosma ◽  
Cosmas I. Nathanailides
Keyword(s):  
Shelf Life ◽  
Food Packaging ◽  
Modified Atmosphere Packaging ◽  
High Water ◽  
Edible Films ◽  
Nitrogenous Compounds ◽  
Quality Properties ◽  
Unsaturated Lipids ◽  
Active Food Packaging ◽  
Seafood Products

Seafood products are highly perishable, owing to their high water activity, close to neutral pH, and high content of unsaturated lipids and non-protein nitrogenous compounds. Thus, such products require immediate processing and/or packaging to retain their safety and quality. At the same time, consumers prefer fresh, minimally processed seafood products that maintain their initial quality properties. The present article aims to review the literature over the past decade on: (i) innovative, individual packaging technologies applied to extend the shelf life of fish and fishery products, (ii) the most common combinations of the above technologies applied as multiple hurdles to maximize the shelf life of seafood products, and (iii) the respective food packaging legislation. Packaging technologies covered include: Modified atmosphere packaging; vacuum packaging; vacuum skin packaging; active food packaging, including oxygen scavengers; carbon dioxide emitters; moisture regulators; antioxidant and antimicrobial packaging; intelligent packaging, including freshness indicators; time–temperature indicators and leakage indicators; retort pouch processing and edible films; coatings/biodegradable packaging, used individually or in combination for maximum preservation potential.

Ligand Fishing with Cellular Membrane-Coated Magnetic Beads: A New Method for the Screening of Potentially Active Compounds from Natural Products

2017 ◽  
Vol 80 (10) ◽  
pp. 1517-1525 ◽  
Author(s):  
Cheng Tang ◽  
Ruizhi Mao ◽  
Fang Liu ◽  
Yaming Yu ◽  
Liang Xu ◽  
...  
Keyword(s):  
Natural Products ◽  
Magnetic Beads ◽  
Cellular Membrane ◽  
New Method ◽  
Active Compounds ◽  
Ligand Fishing

scholarly journals An Improved Transwell Design for Microelectrode Ion-Flux Measurements

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 273
Author(s):  
Boris Buchroithner ◽  
Pavel Spurný ◽  
Sandra Mayr ◽  
Johannes Heitz ◽  
Dmitry Sivun ◽  
...  
Keyword(s):  
Umbilical Vein ◽  
Cell Monolayer ◽  
Three Dimensional ◽  
Cellular Membrane ◽  
Ion Flux ◽  
Direct Access ◽  
Cell Contact ◽  
Culture Dish ◽  
Tissue Culture Dish ◽  
Transwell System

The microelectrode ion flux estimation (MIFE) is a powerful, non-invasive electrophysiological method for cellular membrane transport studies. Usually, the MIFE measurements are performed in a tissue culture dish or directly with tissues (roots, parts of the plants, and cell tissues). Here, we present a transwell system that allows for MIFE measurements on a cell monolayer. We introduce a measurement window in the transwell insert membrane, which provides direct access for the cells to the media in the upper and lower compartment of the transwell system and allows direct cell-to-cell contact coculture. Three-dimensional multiphoton lithography (MPL) was used to construct a 3D grid structure for cell support in the measurement window. The optimal polymer grid constant was found for implementation in transwell MIFE measurements. We showed that human umbilical vein endothelial cells (HUVECs) efficiently grow and maintain their physiological response on top of the polymer structures.

scholarly journals The pH-Induced Specific Area Changes of Unsaturated Lipids Deposited onto a Bubble Interface

Langmuir ◽  
2021 ◽  
Vol 37 (8) ◽  
pp. 2586-2595
Author(s):  
Nicolas Anton ◽  
Philippe Pierrat ◽  
Germain A. Brou ◽  
Gildas K. Gbassi ◽  
Ziad Omran ◽  
...  
Keyword(s):  
Specific Area ◽  
Unsaturated Lipids

scholarly journals Cellular Membrane-Binding Ability of the C-Terminal Cytoplasmic Domain of Human Immunodeficiency Virus Type 1 Envelope Transmembrane Protein gp41

2001 ◽  
Vol 75 (20) ◽  
pp. 9925-9938 ◽  
Author(s):  
Steve S.-L. Chen ◽  
Sheau-Fen Lee ◽  
Chin-Tien Wang
Keyword(s):  
Amino Acids ◽  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Membrane Binding ◽  
Cytoplasmic Tail ◽  
Cellular Membrane ◽  
C Terminus ◽  
Immunodeficiency Virus

ABSTRACT The amphipathic α-helices located in the cytoplasmic tail of the envelope (Env) transmembrane glycoprotein gp41 of human immunodeficiency virus type 1 have been implicated in membrane association and cytopathicity. Deletion of the last 12 amino acids in the C terminus of this domain severely impairs infectivity. However, the nature of the involvement of the cytoplasmic tail in Env-membrane interactions in cells and the molecular basis for the defect in infectivity of this mutant virus are still poorly understood. In this study we examined the interaction of the cytoplasmic tail with membranes in living mammalian cells by expressing a recombinant cytoplasmic tail fragment and an Escherichia coli β-galactosidase/cytoplasmic tail fusion protein, both of them lacking gp120, the gp41 ectodomain, and the transmembrane region. We found through cell fractionation, in vivo membrane flotation, and confocal immunofluorescence studies that the cytoplasmic tail contained determinants to be routed to a perinuclear membrane region in cells. Further mapping showed that each of the three lentivirus lytic peptide (LLP-1, LLP-2, and LLP-3) sequences conferred this cellular membrane-targeting ability. Deletion of the last 12 amino acids from the C terminus abolished the ability of the LLP-1 motif to bind to membranes. High salt extraction, in vitro transcription and translation, and posttranslational membrane binding analyses indicated that the β-galactosidase/LLP fusion proteins were inserted into membranes via the LLP sequences. Subcellular fractionation and confocal microscopy studies revealed that each of the LLP motifs, acting in a position-independent manner, targeted non-endoplasmic reticulum (ER)-associated β-galactosidase and enhanced green fluorescence protein to the ER. Our study provides a basis for the involvement of the gp41 cytoplasmic tail during Env maturation and also supports the notion that the membrane apposition of the C-terminal cytoplasmic tail plays a crucial role in virus-host interaction.

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