Apparent New Modes of Antimalarial Action Detected by Inhibited Incorporation of Adenosine-8-3H into Nucleic Acids of Plasmodium berghei

1969 ◽  
Vol 134 (9) ◽  
pp. 1000-1006 ◽  
Author(s):  
K. Van Dyke ◽  
C. Szustkiewicz
Keyword(s):  
Nucleic Acids ◽  
Plasmodium Berghei ◽  
Antimalarial Action

scholarly journals Studies on the Nucleic Acids of the Malaria Parasite, Plasmodium Berghei (Vincke & Lips)

1953 ◽  
Vol 6 (2) ◽  
pp. 234 ◽  
Author(s):  
PR Whitfeld
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Red Blood Cells ◽  
Plasmodium Berghei ◽  
Acid Content ◽  
Blood Cells ◽  
Malaria Parasite ◽  
Nucleic Acid Content ◽  
Solid Residue ◽  
Parasite Plasmodium

Changes in� the nucleic acid content of the solid residue obtained by haemolysing the blood of mice infected with Plasmodium berghei have been examined. The residue from blood in which 25 per cent. of the red blood cells were parasitized contained 20-25 times as much ribosenucleic acid (RNA) and 12 times as much desoxyribosenucleic acid (DNA) as the residue from uninfected blood.

scholarly journals Regulation of heme polymerizing activity and the antimalarial action of chloroquine.

1997 ◽  
Vol 41 (11) ◽  
pp. 2461-2465 ◽  
Author(s):  
C D Fitch ◽  
A C Chou
Keyword(s):  
Body Weight ◽  
Standard Deviation ◽  
Plasmodium Berghei ◽  
Regulatory Process ◽  
A Chain ◽  
High Level ◽  
Polymerase I ◽  
Antimalarial Action

Mice infected with Plasmodium berghei served as donors of erythrocytes with a high level of parasitemia for the study of ferriprotoporphyrin IX (FP) polymerization. Six hours after treatment of these mice with 3 micromol of chloroquine per 25 g of body weight, there were significant losses of heme polymerase I (HPA I). For chloroquine-susceptible (CS) P. berghei, the rate of FP polymerization decreased from 541 +/- 42 (mean +/- standard deviation; n = 12) to 51 +/- 19 (n = 8) nmol of FP polymerized per h per ml of packed erythrocytes (normalized to represent 1,000 parasites per 1,000 erythrocytes). For chloroquine-resistant (CR) P. berghei, the rate decreased from 284 +/- 19 (n = 16) to 124 +/- 11 (n = 6) nmol per h per ml. The chloroquine-induced loss of HPA I was accompanied by the accumulation of unpolymerized FP in CS P. berghei but not in CR P. berghei, which is consistent with the hypothesis that FP mediates the antimalarial action of chloroquine. Quinine treatment partially reversed the effects of chloroquine in CS P. berghei but not in CR P. berghei. Cycloheximide treatment antagonized the effects of chloroquine in both lines of parasites. To explain these findings, we propose that chloroquine, quinine, and cycloheximide perturb a regulatory process for HPA I. Furthermore, we propose that when chloroquine engages its target in the regulatory process, it initiates a chain of events which culminates in increased production, accessibility, or reactivity of a regulator (inactivator) of HPA I.

Plasmodium berghei: The antimalarial action of artemisinin and sodium artelinate in vivo and in vitro, studied by flow cytometry

1990 ◽  
Vol 70 (2) ◽  
pp. 115-123 ◽  
Author(s):  
Ph.H. van Vianen ◽  
D.L. Klayman ◽  
A.J. Lin ◽  
C.B. Lugt ◽  
A.L. van Engen ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Plasmodium Berghei ◽  
Antimalarial Action

Electron Microscopy of Nucleic Acids

1974 ◽  
Vol 32 ◽  
pp. 302-303
Author(s):  
Norman Davidson
Keyword(s):  
Electron Microscopy ◽  
Nucleic Acids ◽  
Basic Protein ◽  
Molecular Biologist ◽  
Topological Properties ◽  
Protein Film ◽  
Polynucleotide Chain

The basic protein film technique for mounting nucleic acids for electron microscopy has proven to be a general and powerful tool for the working molecular biologist in characterizing different nucleic acids. It i s possible to measure molecular lengths of duplex and single-stranded DNAs and RNAs. In particular, it is thus possible to as certain whether or not the nucleic acids extracted from a particular source are or are not homogeneous in length. The topological properties of the polynucleotide chain (linear or circular, relaxed or supercoiled circles, interlocked circles, etc. ) can also be as certained.

mRNA localization by Electron microscopic in situ hybridization

1991 ◽  
Vol 49 ◽  
pp. 430-431
Author(s):  
J. A. Pollock ◽  
M. Martone ◽  
T. Deerinck ◽  
M. H. Ellisman
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Nucleic Acids ◽  
Recombinant Dna ◽  
Light And Electron Microscopy ◽  
Electron Microscopic ◽  
High Voltage Electron Microscopy ◽  
Functional Sites ◽  
Voltage Electron

Localization of specific proteins in cells by both light and electron microscopy has been facilitate by the availability of antibodies that recognize unique features of these proteins. High resolution localization studies conducted over the last 25 years have allowed biologists to study the synthesis, translocation and ultimate functional sites for many important classes of proteins. Recently, recombinant DNA techniques in molecular biology have allowed the production of specific probes for localization of nucleic acids by “in situ” hybridization. The availability of these probes potentially opens a new set of questions to experimental investigation regarding the subcellular distribution of specific DNA's and RNA's. Nucleic acids have a much lower “copy number” per cell than a typical protein, ranging from one copy to perhaps several thousand. Therefore, sensitive, high resolution techniques are required. There are several reasons why Intermediate Voltage Electron Microscopy (IVEM) and High Voltage Electron Microscopy (HVEM) are most useful for localization of nucleic acids in situ.

Nucleic Acid Molecules Prepared by Monolayer Techniques

1972 ◽  
Vol 30 ◽  
pp. 178-179
Author(s):  
Dimitrij Lang
Keyword(s):  
Electron Microscopy ◽  
Standard Deviation ◽  
Nucleic Acid ◽  
Cytochrome C ◽  
Nucleic Acids ◽  
Contour Length ◽  
Sample Standard Deviation ◽  
Molecular Weights ◽  
Length Measurements ◽  
Protein Monolayer

The success of the protein monolayer technique for electron microscopy of individual DNA molecules is based on the prevention of aggregation and orientation of the molecules during drying on specimen grids. DNA adsorbs first to a surface-denatured, insoluble cytochrome c monolayer which is then transferred to grids, without major distortion, by touching. Fig. 1 shows three basic procedures which, modified or not, permit the study of various important properties of nucleic acids, either in concert with other methods or exclusively:1) Molecular weights relative to DNA standards as well as number distributions of molecular weights can be obtained from contour length measurements with a sample standard deviation between 1 and 4%.

Snapshot blotting: The transfer of nucleic acids and nucleoprotein complexes from electrophoresis gels to EM grids

1992 ◽  
Vol 50 (1) ◽  
pp. 762-763
Author(s):  
Stephen D. Jett
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Nucleic Acid Binding ◽  
Mobility Shift ◽  
Carbon Coated ◽  
Nucleoprotein Complexes ◽  
Mobility Shift Assay ◽  
Protein Nucleic Acid ◽  
Gel Mobility Shift ◽  
Nucleic Acid Interactions

The electrophoresis gel mobility shift assay is a popular method for the study of protein-nucleic acid interactions. The binding of proteins to DNA is characterized by a reduction in the electrophoretic mobility of the nucleic acid. Binding affinity, stoichiometry, and kinetics can be obtained from such assays; however, it is often desirable to image the various species in the gel bands using TEM. Present methods for isolation of nucleoproteins from gel bands are inefficient and often destroy the native structure of the complexes. We have developed a technique, called “snapshot blotting,” by which nucleic acids and nucleoprotein complexes in electrophoresis gels can be electrophoretically transferred directly onto carbon-coated grids for TEM imaging.

Ultrastructural analysis of the spatial distribution of MRNA

1992 ◽  
Vol 50 (1) ◽  
pp. 552-553
Author(s):  
Gary Bassell ◽  
Robert H. Singer
Keyword(s):  
Electron Microscopy ◽  
Spatial Distribution ◽  
In Situ Hybridization ◽  
High Resolution ◽  
Nucleic Acids ◽  
Colloidal Gold ◽  
Dna Probe ◽  
Nucleotide Analogs ◽  
Gold Particles

We have been investigating the spatial distribution of nucleic acids intracellularly using in situ hybridization. The use of non-isotopic nucleotide analogs incorporated into the DNA probe allows the detection of the probe at its site of hybridization within the cell. This approach therefore is compatible with the high resolution available by electron microscopy. Biotinated or digoxigenated probe can be detected by antibodies conjugated to colloidal gold. Because mRNA serves as a template for the probe fragments, the colloidal gold particles are detected as arrays which allow it to be unequivocally distinguished from background.

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