In-Vivo Electrochemistry: What Can We Learn about Living Systems?

2008 ◽  
Vol 108 (7) ◽  
pp. 2462-2481 ◽  
Author(s):  
George S. Wilson ◽  
Michael A. Johnson
Keyword(s):  
Living Systems ◽  
In Vivo Electrochemistry

scholarly journals A novel method for visualizing and tracking endogenous mRNA in a specific cell population in pathological neovascularization

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Md Imam Uddin ◽  
Tyler C. Kilburn ◽  
Sara Z. Jamal ◽  
Craig L. Duvall ◽  
John S. Penn
Keyword(s):  
Real Time ◽  
Disease Burden ◽  
Ex Vivo ◽  
Expression Patterns ◽  
Fluorescence Emission ◽  
High Sensitivity ◽  
Living Systems ◽  
Specific Cell ◽  
Potential Marker

AbstractDiabetic retinopathy, retinopathy of prematurity and retinal vein occlusion are potentially blinding conditions largely due to their respective neovascular components. The development of real-time in vivo molecular imaging methods, to assess levels of retinal neovascularization (NV), would greatly benefit patients afflicted with these conditions. mRNA hybridization techniques offer a potential method to image retinal NV. The success of these techniques hinges on the selection of a target mRNA whose tissue levels and spatial expression patterns correlate closely with disease burden. Using a model of oxygen-induced retinopathy (OIR), we previously observed dramatic increases in retinal endoglin that localized to neovascular structures (NV), directly correlating with levels of neovascular pathology. Based on these findings, we have investigated Endoglin mRNA as a potential marker for imaging retinal NV in OIR mice. Also of critical importance, is the application of innovative technologies capable of detecting mRNAs in living systems with high sensitivity and specificity. To detect and visualize endoglin mRNA in OIR mice, we have designed and synthesized a novel imaging probe composed of short-hairpin anti-sense (AS) endoglin RNA coupled to a fluorophore and black hole quencher (AS-Eng shRNA). This assembly allows highly sensitive fluorescence emission upon hybridization of the AS-Eng shRNA to cellular endoglin mRNA. The AS-Eng shRNA is further conjugated to a diacyl-lipid (AS-Eng shRNA–lipid referred to as probe). The lipid moiety binds to serum albumin facilitating enhanced systemic circulation of the probe. OIR mice received intraperitoneal injections of AS-Eng shRNA–lipid. Ex vivo imaging of their retinas revealed specific endoglin mRNA dependent fluorescence superimposed on neovascular structures. Room air mice receiving AS-Eng shRNA–lipid and OIR mice receiving a non-sense control probe showed little fluorescence activity. In addition, we found that cells in neovascular lesions labelled with endoglin mRNA dependent fluorescence, co-labelled with the macrophage/microglia-associated marker IBA1. Others have shown that cells expressing macrophage/microglia markers associate with retinal neovascular structures in proportion to disease burden. Hence we propose that our probe may be used to image and to estimate the levels of retinal neovascular disease in real-time in living systems.

Engineering cooperative patterns in multi-species bacterial colonies

2019 ◽  
Author(s):  
A. I. Curatolo ◽  
N. Zhou ◽  
Y. Zhao ◽  
C. Liu ◽  
A. Daerr ◽  
...  
Keyword(s):  
Population Level ◽  
Spatial Arrangement ◽  
Cell Types ◽  
Living Systems ◽  
Cellular Interactions ◽  
Cellular Motility ◽  
Periodic Patterns ◽  
Form Complex ◽  
Theoretical Approaches

Self-organization is a hallmark of all living systems [1]. In particular, coordinated cellular behavior, commonly orchestrated at the population level through reciprocal interactions among different cell species [2–4], regulates the spatial arrangement of specialized cell types to generate tissue patterning and form complex body layouts [5, 6]. The overwhelming complexity of living systems, however, makes deciphering the underlying mechanisms difficult and limits our knowledge of basic pattern-forming mechanism in vivo [7, 8]. A successful strategy is then to work with synthetic, engineered systems, in which cellular interactions can be more easily tailored and studied [9–13]. Here, we demonstrate a simple mechanism through which different populations of cells can self-organize in periodic patterns. Programmed population interactions are shown to lead to coordinated out-ofphase spatial oscillations of two engineered populations of Escherichia coli. Using a combination of experimental and theoretical approaches, we show how such patterns arise autonomously from reciprocal density-dependent activation of cellular motility between the two species, without the need of any preexisting positional or orientational cues. Moreover, by re-designing the interaction, the original out-of-phase spatial oscillation rhythm of the two populations can be accordingly turned into in-phase oscillations. The robustness and versatility of the underlying pattern-formation process suggest that it could both be generically encountered in nature, for instance in the complex bacterial ecosystems found in biofilms [14–16], and used to promote the mixing or demixing of active particles in a controlled way.

In vivo electrochemistry: behavior of micro electrodes in brain tissue

1979 ◽  
Vol 100 (1-2) ◽  
pp. 23-31 ◽  
Author(s):  
H.-Y. Cheng ◽  
J. Schenk ◽  
R. Huff ◽  
R.N. Adams
Keyword(s):  
Brain Tissue ◽  
Electrochemistry Behavior ◽  
In Vivo Electrochemistry

NMR studies of enzymatic rates in vitro and in vivo by magnetization transfer

1984 ◽  
Vol 17 (1) ◽  
pp. 83-124 ◽  
Author(s):  
J. R. Alger ◽  
R. G. Shulman
Keyword(s):  
Creatine Kinase ◽  
Chemical Reactions ◽  
Magnetization Transfer ◽  
Living Systems ◽  
Nmr Studies ◽  
Wide Range ◽  
Potential Applications

Magnetization transfer techniques are specialized NMR experiments which can measure the rate of chemical reactions while concentrations of products and reactants are maintained constant. These techniques are being used to measure the rates of enzyme catalysed reactions in a variety of living systems and in vitro. The magnetization transfer measurements in vivo of the ATP synthetase and the creatine kinase reactions have been particularly useful in describing rates of major energy transducing reactions involving ATP and phosphocreatine. As a result, a wide range of biomedicai scientists are becoming aware of the potentials of these techniques. The purpose of this review is thus threefold: first, to present a concise, conceptual review of the underlying principles for these non-specialists; secondly, to review the important biochemical applications of the method which have appeared, and thirdly, to discuss potential applications and limitations of the method.

In vivo electrochemistry - principles and applications

Life Sciences ◽  
1987 ◽  
Vol 41 (7) ◽  
pp. 865-868 ◽  
Author(s):  
Keith F. Martin ◽  
Charles A. Marsden
Keyword(s):  
In Vivo Electrochemistry
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