A Torrent of Viral Isolates: the Early Years of Diagnostic Virology

The Genesis and Internal Dynamics of El Salvador's People's Revolutionary Army, 1970–1976

Behavioral and Brain Sciences ◽

10.1017/s0140525x13009850 ◽

2014 ◽

Vol 38 (01) ◽

pp. 102-129

Author(s):

ALBERTO MARTÍN ÁLVAREZ ◽

EUDALD CORTINA ORERO

Keyword(s):

Latin America ◽

El Salvador ◽

Early Years ◽

Left Wing ◽

Internal Dynamics ◽

Internal Coherence ◽

The 1960S

AbstractUsing interviews with former militants and previously unpublished documents, this article traces the genesis and internal dynamics of the Ejército Revolucionario del Pueblo (People's Revolutionary Army, ERP) in El Salvador during the early years of its existence (1970–6). This period was marked by the inability of the ERP to maintain internal coherence or any consensus on revolutionary strategy, which led to a series of splits and internal fights over control of the organisation. The evidence marshalled in this case study sheds new light on the origins of the armed Salvadorean Left and thus contributes to a wider understanding of the processes of formation and internal dynamics of armed left-wing groups that emerged from the 1960s onwards in Latin America.

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Electron microscopy in diagnostic virology

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100110702 ◽

1984 ◽

Vol 42 ◽

pp. 70-73

Author(s):

S. E. Miller

Keyword(s):

Electron Microscopy ◽

Tissue Culture ◽

Molecular Identification ◽

Point Of View ◽

Negative Stain ◽

Viral Diagnosis ◽

Electron Microscopist ◽

Diagnostic Virology

The techniques for detecting viruses are many and varied including FAT, ELISA, SPIRA, RPHA, SRH, TIA, ID, IEOP, GC (1); CF, CIE (2); Tzanck (3); EM, IEM (4); and molecular identification (5). This paper will deal with viral diagnosis by electron microscopy and will be organized from the point of view of the electron microscopist who is asked to look for an unknown agent--a consideration of the specimen and possible agents rather than from a virologist's view of comparing all the different viruses. The first step is to ascertain the specimen source and select the method of preparation, e. g. negative stain or embedment, and whether the sample should be precleared by centrifugation, concentrated, or inoculated into tissue culture. Also, knowing the type of specimen and patient symptoms will lend suggestions of possible agents and eliminate some viruses, e. g. Rotavirus will not be seen in brain, nor Rabies in stool, but preconceived notions should not prejudice the observer into missing an unlikely pathogen.

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Image quality vs data obtainment in biological electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100141950 ◽

1986 ◽

Vol 44 ◽

pp. 42-43

Author(s):

J. E. Johnson

Keyword(s):

Electron Microscopy ◽

Endoplasmic Reticulum ◽

Electron Beam ◽

Image Quality ◽

High Speed ◽

Early Period ◽

Early Years ◽

Fluorescent Screen ◽

Embedding Medium

In the early years of biological electron microscopy, scientists had their hands full attempting to describe the cellular microcosm that was suddenly before them on the fluorescent screen. Mitochondria, Golgi, endoplasmic reticulum, and other myriad organelles were being examined, micrographed, and documented in the literature. A major problem of that early period was the development of methods to cut sections thin enough to study under the electron beam. A microtome designed in 1943 moved the specimen toward a rotary “Cyclone” knife revolving at 12,500 RPM, or 1000 times as fast as an ordinary microtome. It was claimed that no embedding medium was necessary or that soft embedding media could be used. Collecting the sections thus cut sounded a little precarious: “The 0.1 micron sections cut with the high speed knife fly out at a tangent and are dispersed in the air. They may be collected... on... screens held near the knife“.

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A combined pseudoreplica-immunocytochemical technique for research and diagnostic virology

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100162065 ◽

1990 ◽

Vol 48 (3) ◽

pp. 900-901

Author(s):

Blayne Fritz ◽

Stanley J. Naides ◽

Kenneth Moore

Keyword(s):

Phosphotungstic Acid ◽

Immunogold Labelling ◽

Uranyl Acetate ◽

Distilled Water ◽

Clinical Specimens ◽

Tissue Sections ◽

Specimen Retrieval ◽

Transmission Electron ◽

Viral Particles ◽

Diagnostic Virology

The pseudoreplica method of staining viral particles for visualization by transmission electron microscopy is a very popular technique. The ability to concentrate clinical specimens while semi-embedding viral particles makes it especially well suited for morphologic and diagnostic virology. Immunolabelling viral particles with colloidal gold is a technique frequently employed by both research and diagnostic virologists. We have characterized a procedure which provides the advantage of both by modifying and combining pseudoreplica staining and immunogold labelling.Modification of specimen retrieval and delay of staining allows us to utilize pseudoreplica processed specimens within our standard immunogold labelling protocol. In brief, we absorbed samples onto 2% agarose, added.25% Formvar and wicked dry. We then floated the Formvar-virus film onto double distilled water, added grids and retrieved with parafilm. The Formvar-virus specimens were then treated as thin tissue sections within our standard two stage immunolabelling protocol. Following completion of immunogold labelling; each grid was negatively stained with phosphotungstic acid or uranyl acetate contrast stains.

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