scholarly journals The effect of speed of deoxygenation on the percentage of aligned hemoglobin in sickle cells. Application of differential polarization microscopy.

1988 ◽  
Vol 263 (9) ◽  
pp. 4338-4346
Author(s):  
W E Mickols ◽  
J D Corbett ◽  
M F Maestre ◽  
I Tinoco ◽  
J Kropp ◽  
...  
Keyword(s):  
Polarization Microscopy ◽  
Sickle Cells

Differential polarization microscopy: Theory and applications

1988 ◽  
Vol 46 ◽  
pp. 60-61
Author(s):  
Laura Finzi ◽  
David Beach ◽  
Carlos Bustamante ◽  
Gyozo Garab
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Linear Dichroism ◽  
Polarization Microscopy ◽  
Difference Image ◽  
Sickle Cells ◽  
Polarization Image ◽  
Hb S ◽  
Low Pressures

In Differential Polarization Microscopy two images of an object obtained usina orthogonal incident polarizations are subtracted from each other. The resulting difference image can display both magnitude and sign whose values will vary according to location in the image and the value of the local optical anisotropy of the object.Thus, Linear Dichroism and Circular Dichroism images of an object can be obtained.a) In-situ studies of the polymerization of Hb S in red blood sickle cells.-Mutant hemoglobin Hb S, present in sickle cell anemia, tends to aggregate at low pressures of oxygen forming polymers. Furthermore various polymers can align side by side. Using differential polarization image we can detect the angle of alignment and amount of polymerized HbS inside a red blood cell. We have also developed a supra-vital method for following the reversible process of polymerization and alignment inside a red blood cell, as a function of the oxygen pressure.

Differential polarization imaging of sickled cells

1988 ◽  
Vol 46 ◽  
pp. 62-63
Author(s):  
Marcos F. Maestre
Keyword(s):  
Optical Properties ◽  
Theoretical Approach ◽  
Polarized Light ◽  
Polarization Microscopy ◽  
Spectroscopic Techniques ◽  
Polarization Imaging ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Microscopic Scale ◽  
Chiral Structures

Recently we have developed a form of polarization microscopy that forms images using optical properties that have previously been limited to macroscopic samples. This has given us a new window into the distribution of structure on a microscopic scale. We have coined the name differential polarization microscopy to identify the images obtained that are due to certain polarization dependent effects. Differential polarization microscopy has its origins in various spectroscopic techniques that have been used to study longer range structures in solution as well as solids. The differential scattering of circularly polarized light has been shown to be dependent on the long range chiral order, both theoretically and experimentally. The same theoretical approach was used to show that images due to differential scattering of circularly polarized light will give images dependent on chiral structures. With large helices (greater than the wavelength of light) the pitch and radius of the helix could be measured directly from these images.

Modulated polarization microscopy displays the dynamics of cytoskeletal structures in living, motile cells

1995 ◽  
Vol 53 ◽  
pp. 902-903
Author(s):  
J. R. Kuhn ◽  
M. Poenie
Keyword(s):  
Mitotic Spindle ◽  
Actin Filaments ◽  
Cell Shape ◽  
Dynamic Structure ◽  
Living Cells ◽  
Cytoskeletal Proteins ◽  
Polarization Microscopy ◽  
Video Enhancement ◽  
Ultrastructural Studies ◽  
Motile Cells

Cell shape and movement are controlled by elements of the cytoskeleton including actin filaments an microtubules. Unfortunately, it is difficult to visualize the cytoskeleton in living cells and hence follow it dynamics. Immunofluorescence and ultrastructural studies of fixed cells while providing clear images of the cytoskeleton, give only a static picture of this dynamic structure. Microinjection of fluorescently Is beled cytoskeletal proteins has proved useful as a way to follow some cytoskeletal events, but long terry studies are generally limited by the bleaching of fluorophores and presence of unassembled monomers.Polarization microscopy has the potential for visualizing the cytoskeleton. Although at present, it ha mainly been used for visualizing the mitotic spindle. Polarization microscopy is attractive in that it pro vides a way to selectively image structures such as cytoskeletal filaments that are birefringent. By combing ing standard polarization microscopy with video enhancement techniques it has been possible to image single filaments. In this case, however, filament intensity depends on the orientation of the polarizer and analyzer with respect to the specimen.

How do sickle cells become dehydrated?

2001 ◽  
Vol 2 (3) ◽  
pp. 200-205 ◽  
Author(s):  
Patrick Merciris ◽  
Françoise Giraud
Keyword(s):  
Sickle Cells

scholarly journals Quantitative linear dichroism imaging of molecular processes in living cells made simple by open software tools

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Alexey Bondar ◽  
Olga Rybakova ◽  
Josef Melcr ◽  
Jan Dohnálek ◽  
Petro Khoroshyy ◽  
...  
Keyword(s):  
Biological Systems ◽  
Linear Dichroism ◽  
Quantitative Information ◽  
Living Cells ◽  
Software Tools ◽  
Model Systems ◽  
Membrane Properties ◽  
Polarization Microscopy ◽  
Molecular Processes ◽  
Wide Range

AbstractFluorescence-detected linear dichroism microscopy allows observing various molecular processes in living cells, as well as obtaining quantitative information on orientation of fluorescent molecules associated with cellular features. Such information can provide insights into protein structure, aid in development of genetically encoded probes, and allow determinations of lipid membrane properties. However, quantitating and interpreting linear dichroism in biological systems has been laborious and unreliable. Here we present a set of open source ImageJ-based software tools that allow fast and easy linear dichroism visualization and quantitation, as well as extraction of quantitative information on molecular orientations, even in living systems. The tools were tested on model synthetic lipid vesicles and applied to a variety of biological systems, including observations of conformational changes during G-protein signaling in living cells, using fluorescent proteins. Our results show that our tools and model systems are applicable to a wide range of molecules and polarization-resolved microscopy techniques, and represent a significant step towards making polarization microscopy a mainstream tool of biological imaging.

Massive Sequestration of Human Sickle Cells After Transfusion to a Baboon

1986 ◽  
Vol 15 (2) ◽  
pp. 71-79
Author(s):  
Antoine K. Fomufod ◽  
Oswaldo Castro ◽  
Lynnard J. Slaughter ◽  
Laval N. Cothran ◽  
Norman R. Hayes ◽  
...  
Keyword(s):  
Sickle Cells

A study of membrane lipids from dehydration-acclimated Brassica napus root cells: formation of a cubic phase under physiological conditions

1990 ◽  
Vol 68 (1) ◽  
pp. 102-105 ◽  
Author(s):  
P. Norberg ◽  
K. Larsson ◽  
C. Liljenberg
Keyword(s):  
Water Deficit ◽  
Membrane Lipids ◽  
Phase Behaviour ◽  
Water Deficit Stress ◽  
Cubic Phase ◽  
Polarization Microscopy ◽  
Root Cells ◽  
X Ray ◽  
X Ray Crystallography ◽  
Microsomal Membranes

Rape seedlings were acclimated to evaporative dehydration by exposure to repeated moderate water-deficit stress. The stress program started after 19 days of growth and consisted of three, 24-h stress periods interspersed with 24-h rewatering periods. After the third stress period the roots were harvested and microsomal membranes were isolated. Control plants were grown under equivalent conditions without stress (nonacclimated cells). Total lipids were extracted from the membranes and investigated with X-ray crystallography and polarization microscopy at different degrees of hydration and temperatures. In excess water, the membrane lipids from both acclimated and nonacclimated cells exhibited a cubic phase. The lipids from the nonacclimated cells formed a hexagonal (HII) phase on dehydration. The lipids from the acclimated cells behaved in a different way during dehydration, where the cubic phase was transformed to an L2 phase via an intermediate HII phase. At increasing temperatures, the hydrated cubic phase started to form an L2 phase at 30 °C and was fully converted to the liquid-type state at 42 °C. The mesomorphic phase behaviour is discussed in relation to membrane activity.Key words: water-deficit stress, microsomal membranes, X-ray crystallography, polarization microscopy.

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