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174 results on '"Marsh, Jon N."'

4. Molecularly targeted nanocarriers deliver the cytolytic peptide melittin specifically to tumor cells in mice, reducing tumor growth

Author

Soman, Neelesh R., Baldwin, Steven L., Hu, Grace, Marsh, Jon N., Lanza, Gregory M., Heuser, John E., Arbeit, Jeffrey M., Wickline, Samuel A., and Schlesinger, Paul H.

Subjects
Cholesterol -- Growth, Targeting (Nuclear strategy), Endothelium -- Growth, Cancer -- Care and treatment, Monomolecular films, Peptides -- Growth, Perfluorocarbons, Company growth, Health care industry
Abstract

The in vivo application of cytolytic peptides for cancer therapeutics is hampered by toxicity, nonspecificity, and degradation. We previously developed a specific strategy to synthesize a nanoscale delivery vehicle for cytolytic peptides by incorporating the nonspecific amphipathic cytolytic peptide melittin into the outer lipid monolayer of a perfluorocarbon nanoparticle. Here, we have demonstrated that the favorable pharmacokinetics of this nanocarrier allows accumulation of melittin in murine tumors in vivo and a dramatic reduction in tumor growth without any apparent signs of toxicity. Furthermore, direct assays demonstrated that molecularly targeted nanocarriers selectively delivered melittin to multiple tumor targets, including endothelial and cancer cells, through a hemifusion mechanism. In cells, this hemifusion and transfer process did not disrupt the surface membrane but did trigger apoptosis and in animals caused regression of precancerous dysplastic lesions. Collectively, these data suggest that the ability to restrain the wide-spectrum lytic potential of a potent cytolytic peptide in a nanovehicle, combined with the flexibility of passive or active molecular targeting, represents an innovative molecular design for chemotherapy with broad-spectrum cytolytic peptides for the treatment of cancer at multiple stages., Introduction Host defense peptides are a class of small amphipathic peptides (10-50 aa) found in most eukaryotic cells that serve diverse functions in humans and other species stemming from their [...]

Published
2009
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5. Sensitive ultrasonic delineation of steroid treatment in living dystrophic mice with energy-based and entropy-based radio frequency signal processing

Author

Wallace, Kirk D., Marsh, Jon N., Baldwin, Steven L., Connolly, Anne M., Keeling,Richard, Lanza, Gregory M., Wickline,Samuel A., and Hughes, Michael S.

Subjects
Duchenne muscular dystrophy -- Research, Diagnosis, Ultrasonic -- Equipment and supplies, Diagnosis, Ultrasonic -- Usage, Business, Electronics, Electronics and electrical industries
Abstract

The capability of energy and entropy metrics of radio-frequency ultrasonic backscatter is validated and quantified for differentiation among normal, dystrophic and steroid-treated muscle in the mdx model. Results suggest the delineation of both treated and untreated-mdx biceps from normal controls.

Published
2007

8. Characterization of digital waveforms using thermodynamic analogs: Detection of contrast-targeted tissue in vivo

Author

Hughes, Michael S., Lacy, Elizabeth K., Marsh, Jon N., Carradine, Cordelia, Hyuing Zhang, Lanza, Gregory M., Woodson, Adam K., Wickline, Samuel A., and Allen, John S.

Subjects
Waveforms -- Analysis, Backscattering -- Measurement, Ultrasound imaging -- Methods, Tumors -- Diagnosis, Business, Electronics, Electronics and electrical industries
Abstract

Characterization of backscatter from tumor tissue targeted with a nanoparticle-based ultrasound contrast agent in vivo analogs of thermodynamic quantities is described. Results reveal that the thermodynamic analog is capable of detecting differences in backscattered signals that are not apparent with the B-mode approach.

Published
2006

10. Characterization of digital waveforms using thermodynamic analogs: Applications to detection of materials defects

Author

Hughes, Michael S., Marsh, Jon N., Hall, Christopher S., Savery, David, Lanza, Gregory M., and Wickline, Samuel A.

Subjects
Waveforms -- Analysis, Thermodynamics -- Analysis, Non-destructive testing -- Methods, Business, Electronics, Electronics and electrical industries
Abstract

Characterization of digital signals using analogs of thermodynamic quantities, the topological entropy, Shannon entropy, thermodynamic energy, partition function, specific heat at constant volume was described. The results of applying thermodynamic quantities to a problem from nondestructive materials evaluation, detection of foreign objects embedded near the surface of thin graphite laminates using backscattered waveforms obtained by C-scanning the laminates were reported.

Published
2005

12. Improvements in the ultrasonic contrast of targeted perfluorocarbon nanoparticles using an acoustic transmission line model

Author

Marsh, Jon N., Hall, Christopher S., Scott, Michael J., Fuhrhop, Ralph W., Gaffney, Patrick J., Wickline, Samuel A., and Lanza, Gregory M.

Subjects
Ultrasonics in medicine -- Research, Medical research -- Research, Electronics industry -- Research, Health care industry, Electronics industry, Business, Electronics, Electronics and electrical industries
Abstract

It is proposed that a ligand-targeted, lipid-encapsulated, liquid perfluorodichlorooctane ultrasonic contrast system system with a small nominal particle size be approximated as a simple, thin layer, acoustic transmission line. This model is evaluated, and the ultrasonic reflectivity of different perfluorocarbon formulations with varying acoustic impedances that target either nitrocellulose membranes or plasma thrombi in vitro are compared.

Published
2002

21. High Contrast Ultrasonic Imaging of Resin-Rich Regions in Graphite/Epoxy Composites Using Entropy.

Author

Hughes, Michael S., McCarthy, John E., Bruillard, Paul. J., Marsh, Jon N., and Wickline, Samuel A.

Subjects
ULTRASONIC imaging, GUMS & resins, GRAPHITE, EPOXY compounds, COMPOSITE materials, ENTROPY
Abstract

This study compares different approaches for imaging a near-surface resin-rich defect in a thin graphite/epoxy plate using backscattered ultrasound. The specimen was created by cutting a circular hole in the second ply; this region filled with excess resin from the graphite/epoxy sheets during the curing process. Backscattered waveforms were acquired using a 4 in. focal length, 5MHz center frequency broadband transducer, scanned on a 100x100 grid of points that were 0.03x0.03 in. apart. The specimen was scanned with the defect side closest to the transducer. Consequently, the reflection from the resin-rich region cannot be gated from the large front-wall echo. At each point in the grid 256 waveforms were averaged together and subsequently used to produce peak-to-peak, Signal Energy (sum of squared digitized waveform values), as well as entropy images of two different types (a Renyi entropy, and a joint entropy). As the figure shows, all of the entropy images exhibit better border delineation and defect contrast than the either the peak-to-peak or Signal Energy. The best results are obtained using the joint entropy of the backscattered waveforms with a reference function. Two different references are examined. The first is a reflection of the insonifying pulse from a stainless steel reflector. The second is an approximate optimum obtained from an iterative parametric search. The joint entropy images produced using this reference exhibit three times the contrast obtained in previous studies. [ABSTRACT FROM AUTHOR]

Published
2016
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22. Rapamycin nanoparticles target defective autophagy in muscular dystrophy to enhance both strength and cardiac function

Author

Bibee, Kristin P., primary, Cheng, Ya‐Jian, additional, Ching, James K., additional, Marsh, Jon N., additional, Li, Allison J., additional, Keeling, Richard M., additional, Connolly, Anne M., additional, Golumbek, Paul T., additional, Myerson, Jacob W., additional, Hu, Grace, additional, Chen, Junjie, additional, Shannon, William D., additional, Lanza, Gregory M., additional, Weihl, Conrad C., additional, and Wickline, Samuel A., additional

Published
2014
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24. Programmable nanoparticle functionalization for in vivo targeting

Author

Pan, Hua, primary, Myerson, Jacob W., additional, Hu, Lingzhi, additional, Marsh, Jon N., additional, Hou, Kirk, additional, Scott, Michael J., additional, Allen, John S., additional, Hu, Grace, additional, Roman, Susana San, additional, Lanza, Gregory M., additional, Schreiber, Robert D., additional, Schlesinger, Paul H., additional, and Wickline, Samuel A., additional

Published
2012
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33. Entropy vs. Energy Waveform Processing: A Comparison Based on the Heat Equation.

Author

Hughes, Michael S., McCarthy, John E., Bruillard, Paul J., Marsh, Jon N., and Wickline, Samuel A.

Subjects
ENTROPY, WAVE analysis, HEAT equation, ELECTROMAGNETISM, SOUND waves
Abstract

Virtually all modern imaging devices collect electromagnetic or acoustic waves and use the energy carried by these waves to determine pixel values to create what is basically an "energy" picture. However, waves also carry "information", as quantified by some form of entropy, and this may also be used to produce an "information" image. Numerous published studies have demonstrated the advantages of entropy, or "information imaging", over conventional methods. The most sensitive information measure appears to be the joint entropy of the collected wave and a reference signal. The sensitivity of repeated experimental observations of a slowly-changing quantity may be defined as the mean variation (i.e., observed change) divided by mean variance (i.e., noise). Wiener integration permits computation of the required mean values and variances as solutions to the heat equation, permitting estimation of their relative magnitudes. There always exists a reference, such that joint entropy has larger variation and smaller variance than the corresponding quantities for signal energy, matching observations of several studies. Moreover, a general prescription for finding an "optimal" reference for the joint entropy emerges, which also has been validated in several studies. [ABSTRACT FROM AUTHOR]

Published
2015
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42. Acoustic Molecular Imaging and Targeted Drug Delivery with Perfluorocarbon Nanoparticles.

Author

Lanza, Gregory M., Hughes, Michael. S., Marsh, Jon N., Scott, Michael J., Huiying Zhang, Lacy, Elizabeth K., Allen, John S., and Wickline, Samuel A.

Subjects
MEDICAL imaging systems, MOLECULAR biology, NANOPARTICLES, GLYCOPROTEINS, CELL adhesion molecules, BIOMARKERS
Abstract

Advances in molecular biology and cellular biochemistry are providing new opportunities for diagnostic medical imaging to “see” beyond the anatomical manifestations of disease to the earliest biochemical signatures of disease. Liquid perfluorocarbon nanoparticles provide inherent acoustic contrast when bound to targets, e.g., fibrin deposits in a thrombus, but unbound nanoparticles are undetectable. This nanoparticle platform may be further functionalized with paramagnetic metals, such as gadolinium, or radionuclides, with homing ligands, like anti-αvβ3-integrins, and therapeutic agents. Acoustic imaging of densely distributed biomarkers, e.g., fibrin epitopes, is readily accommodated with fundamental imaging, but for sparse biomarkers, e.g., integrins, we have developed and implemented novel, nonlinear imaging techniques based upon information-theoretic receivers (i.e., thermodynamic receivers). These novel receivers allow sensitive direct imaging of contrast development. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2005
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