Biophysical Parasitology

Dvorak, J A.

Abstract

This project is concerned with (a) analyses of the genetic diversity of Trypanosoma cruzi and its implications to the epidemiology, course, and diagnosis of Chagas' disease; (b) the development of high resolution flow cytometry instrumentation for biomedical research; and (c) the utilization of flow cytometry and low light level video microscopy for the analyses of infectious agents. We have demonstrated that DNA variants of T. cruzi occur at low frequency from a single-cell isolate clone stock. These variants are being characterized. Environmental parameters such as temperature can destabilize the DNA of T. cruzi resulting in the appearance of variant stocks. Drug and radiation-induced T. cruzi mutants have been produced which are resistant to tubercidin, an adenosine analogue. These mutants are being characterized in an attempt to determine the genetic basis for drug resistance.

Funding Agency

• Agency: National Institute of Health (NIH)
• Institute: National Institute of Allergy and Infectious Diseases (NIAID)
• Type: Intramural Research (Z01)
• Project #: 1Z01AI000099-21
• Application #: 3803090
• Support Year: 21
• Fiscal Year: 1991

Institution

• Name: National Institute of Allergy and Infectious Diseases
• Country: United States

Publications

Tokumasu, Fuyuki; Ostera, Graciela R; Amaratunga, Chanaki et al. (2012) Modifications in erythrocyte membrane zeta potential by Plasmodium falciparum infection. Exp Parasitol 131:245-51

Tokumasu, Fuyuki; Nardone, Glenn A; Ostera, Graciela R et al. (2009) Altered membrane structure and surface potential in homozygous hemoglobin C erythrocytes. PLoS One 4:e5828

Ostera, Graciela; Tokumasu, Fuyuki; Oliveira, Fabiano et al. (2008) Plasmodium falciparum: food vacuole localization of nitric oxide-derived species in intraerythrocytic stages of the malaria parasite. Exp Parasitol 120:29-38

Calvo, Eric; Tokumasu, Fuyuki; Marinotti, Osvaldo et al. (2007) Aegyptin, a novel mosquito salivary gland protein, specifically binds to collagen and prevents its interaction with platelet glycoprotein VI, integrin alpha2beta1, and von Willebrand factor. J Biol Chem 282:26928-38

Hayakawa, Eri; Tokumasu, Fuyuki; Nardone, Glenn A et al. (2007) A Mycobacterium tuberculosis-derived lipid inhibits membrane fusion by modulating lipid membrane domains. Biophys J 93:4018-30

Arie, Takayuki; Fairhurst, Rick M; Brittain, Nathaniel J et al. (2005) Hemoglobin C modulates the surface topography of Plasmodium falciparum-infected erythrocytes. J Struct Biol 150:163-9

Tokumasu, Fuyuki; Fairhurst, Rick M; Ostera, Graciela R et al. (2005) Band 3 modifications in Plasmodium falciparum-infected AA and CC erythrocytes assayed by autocorrelation analysis using quantum dots. J Cell Sci 118:1091-8

Tokumasu, Fuyuki; Hwang, Jeeseong; Dvorak, James A (2004) Heterogeneous molecular distribution in supported multicomponent lipid bilayers. Langmuir 20:614-8

Tokumasu, Fuyuki; Jin, Albert J; Feigenson, Gerald W et al. (2003) Atomic force microscopy of nanometric liposome adsorption and nanoscopic membrane domain formation. Ultramicroscopy 97:217-27

Tokumasu, F; Dvorak, J (2003) Development and application of quantum dots for immunocytochemistry of human erythrocytes. J Microsc 211:256-61