Direct Imaging of Live Human Platelets by Flash X-Ray Microscopy

Feder, R.; Banton, V.; Sayre, D.; Costa, J. L.; Baldini, Mario; Kim, Byung Gon

doi:10.1126/science.3964958

Cited by 59 publications

(19 citation statements)

References 9 publications

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“…Recently discovered x-ray microscopy should enable visualization of wet gels, but not real time during gelation, at least as presently configured. To the author's knowledge, this promising method has not yet been applied to gels per se', but "network" structures have been observed within live human platelets (54 Additionally, the signal is often strong enough that even rapidly evolving systems can be followed "live". This feature is especially helpful when the entire angular range can be simultaneously scanned.…”

Section: Direct Methodsmentioning

confidence: 99%

“…which typify the explosive growth in the ancient science of visible microscopy. Although the focus has been on biosystems, there is no reason why these technologies cannot be Downloaded by 54 imported to a wider variety of problems. Of some importance to gels, optical microscopy is essentially non-perturbing and dynamic evolution of structure may be visible in some circumstances (34).…”

Section: Direct Methodsmentioning

confidence: 99%

“…makes this a legitimate gamble. Implicit is the assumption that the microgel particle shares Downloaded by 54 , see 37) can be used to measure the motions, through a gel matrix, of a series of spherically shaped particles with varying sizes. To oversimplify greatly, if, as probe size is raised, a dramatic decrease in diffusivity is found, then the "mesh" size of the polymer gel may be estimated.…”

Section: Direct Methodsmentioning

confidence: 99%

“…Large enough that it is retained by the reticular gel structure, but not so large that its weight destroys the gel. Many workers would agree that Theological measurement is the soundest method for identifying Downloaded by 54 gels. For example, if we place a dilute suspension suspected to be a gel between two horizontal parallel plates and apply a weak static shear strain by displacing the upper plate a small and fixed distance while holding the lower plate still, we expect the true gel to exert a counterbalancing force.…”

Section: Fundamental Considerations the Ferry Definition Abuse Of Thmentioning

confidence: 99%

“…By analogy with typical covalent gels, reversible gel structures are frequently discussed in terms of "crosslinks" Downloaded by 54 which join "network strands". In reversible gels, the crosslinks must be the result of molecular association, but the details vary.…”

Section: A Classification Scheme For Gels: Jishnet and Lattice Gelsmentioning

confidence: 99%

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A Perspective on Reversible Gels and Related Systems

Russo

1987

Reversible Polymeric Gels and Related Systems

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The features common to reversible polymer gels of many types are identified and discussed. The nature of the gel state is carefully defined, and a novel classification scheme based on morphology, rather than chemical or mechanistic considerations, is proposed. The article also serves as an overview to some of the more commonly used techniques used in the study of gels, and as an introduction to some of the current trends in reversible gel research. Some speculations regarding future trends in reversible gel research are presented.Of all the physical states, there is something especially elusive about gels. Systems which gel reversibly are particularly difficult to understand, for the requirement is that an enormous transformation of physical state must occur, usually involving only a small portion of the system. Yet an astounding variety of mechanisms can result in reversible gelation, and it seems that a general understanding of reversible gels will not soon be achieved. Perhaps the greatest universality is presently found in the objectives of gel researchers and the obstacles to meeting them (1). The would-be gel researcher must first confirm positively that the system is a gel. Even this isn't always trivial. Next, the conditions under which reversible gelation occurs must be carefully mapped out. Recent controversies show that this matter is often complex, too.After these preliminaries, a structural analysis of the gel is appropriate. Next, it is often of considerable interest to undertake the kinetic study of how the structure forms during gelation-a question which is often the most difficult of all. Finally, we may add such practical concerns as the commercial utility or biological function of the gel.

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Section: Direct Methodsmentioning

confidence: 99%

Section: Direct Methodsmentioning

confidence: 99%

Section: Direct Methodsmentioning

confidence: 99%

Section: Fundamental Considerations the Ferry Definition Abuse Of Thmentioning

confidence: 99%

Section: A Classification Scheme For Gels: Jishnet and Lattice Gelsmentioning

confidence: 99%

See 3 more Smart Citations

A Perspective on Reversible Gels and Related Systems

Russo

1987

Reversible Polymeric Gels and Related Systems

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Morphologic and ultrastructural evidence for interleukin‐6 induced platelet activation

Oleksowicz

Mrowiec

Isaacs³

et al. 1995

American J Hematol

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The in vitro effect of IL-6 on platelet activation was investigated. When human platelets were incubated with high (1,000 ng/ml) or low (1 ng/ml) dose IL-6, expression of GMP-140 was enhanced by 42% (N = 6; P < 0.009) and 46% (N = 6; P < 0.061) in 1 hr low and high dose IL-6-platelet incubations, respectively, as assessed by flow cytometry. In platelet specimens incubated with high dose IL-6 for 3 hr, a 70% (N = 6; P < 0.009) increase in GMP-140 expression over control was observed. Parallel high dose IL-6 incubations subjected to scanning electron microscopic studies revealed a 3.4-fold increase (N = 6; P < 0.001) in spheroid morphologic platelet forms in 1 hr incubations in comparison to control platelet preparations, whereas in 3 hr IL-6-platelet incubations, a 96% increase in dendritic platelet forms was observed (N = 6; P < 0.001). Significant increases in platelet ATP levels were observed in both 1 min and 1 hr high dose and low dose IL-6 platelet incubations. In 3 hr high dose-IL-6 platelet incubations, a significant 18% (N = 8; P < 0.001) decrease in platelet ATP was parallelled by a significant 40% increase (N = 8; P < 0.014) in plasma ATP in the same specimens. This increased plasma ATP was highly correlated with a reduction in platelet ATP when analyzed by bivariate regression analysis. Lastly, transmission electron microscopic analysis demonstrated a significant reduction in dense granule number and ratio of dense granule surface area/cell surface area in 3 hr high dose IL-6 incubations. These findings suggests that IL-6 activates platelets in vitro.

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