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R Warocquier

Publications and source records attributed to R Warocquier.

18 recordsLinked to original sources
PubMed1978

The use of a measles latex reagent for the determination of measles antibodies and in a specific test for multiple sclerosis.

Measles virus antigens covalently linked to latex spheres were used for measuring measles-specific antibodies in a direct agglutination test either in microtitre plates or as a rapid slide-agglutination test. The titres were compared to that obtained by conventional assays. The measles-latex spheres were also used as the antigen for a radio-immuno assay. By incorporating a 14C-radioactive marker into the measles-latex spheres their interaction with lymphocytes from multiple sclerosis and control patients was determined. Lymphocytes from multiple sclerosis patients reacted with a higher percentage of beads at low bead/lymphocyte ratios compared with controls, whereas the reverse was found when the ratio of beads was increased.

Antibodies, Viral↗
PubMed1978

Isolation and phenotypic characterization of human adenovirus type 2 temperature-sensitive mutants.

Thirty-nine temperature-sensitive (ts) mutants that fail to grow at 39.5 degrees C but develop normally at 33 degrees C have been isolated from a nitrous-acid-treated stock of a wild-type strain of type 2 human adenovirus. The frequency of ts mutants among the surviving viruses was about 10%. Complementation tests in doubly infected cell cultures at restrictive temperature permitted the assignment of 19 of these mutants to 11 complementation groups. They are characterized phenotypically according to their soluble capsid antigen production quantified by two-dimensional immunoelectrophoresis, virus DNA synthesis, as measured by alkaline sucrose gradient sedimentation of 34S DNA, and virion morphogenesis, as analysed by electron microscopy os cell sections. Two complementation groups were defective for DNA synthesis, four for soluble hexon production and two groups for total penton (penton base + fibre), while one group revealed no fibre production. Two complementation groups presented a normal antigen pattern, but the particles exhibited altered morphology as observed in cell sections.

Adenoviruses, Human↗
PubMed1976

Adenovirus protein maturation at 42 degrees C.

Incubation of adenovirus type 2 infected cells at 42 degrees C resulted in an inhibition of assembly of virus particles although all the major viral structural polypeptides and virus-induced cellular polypeptides so far identified were detected by electrophoretic analysis. Selective high salt-acid-urea extraction of low mol. wt. polypeptides revealed the absence of protein VII at 42 degrees C whereas precursor polypeptide P-VII and core protein V were found. Pulse-chase and temperature shift experiments indicated that cleavage of P-VII into VII was a reversible thermosensitive process, requiring de novo protein synthesis after shift-down to 37 degrees C. Virus particles assembled at 37 degrees C after transfer from 42 to 37 degrees C contained both viral DNA and polypeptides pre-labelled during the eclipse phase at 42 degrees C, including core protein VII.

Adenoviridae↗
PubMed1975

Quantitation of adenovirus soluble antigens by crossed immunoelectrophoresis: application to serological characterization of mutants.

The two-dimensional immunoelectrophoresis technique was applied to adenovirus type 2 soluble antigens. Electrophoresis of adenovirus-infected HeLa cell extracts in adenovirus antibody-containing agarose gel permitted us to assay for hexon, assembled penton, free penton base and free fiber simultaneously in one single experiment. This technique was routinely used to characterize the adenovirus type 2 temperature-sensitive mutants.

Adenoviridae↗
PubMed1971

Improved method for virus structural polypeptide analysis on dissociating acylamide gel.

A method is described in which polypeptides can be separated, with a high band resolution, by electrophoresis through "pore gradient" acrylamide gel (15 cm in length) in a sodium dodecyl sulfate-urea dissociating system. The applicability of this technique to the analysis of virus structural components was examined with the adenovirus type 2 model system.

Adenoviridae↗
PubMed1969

Biochemical studies on adenovirus multiplication. XVI. Transcription of the adenovirus genome during abortive infection of elevated temperatures.

The synthesis of infectious virus is reduced by 99% in adenovirus type 2-infected KB cells maintained at 42 C in suspension. Studies to delineate the steps in virus biosynthesis blocked at 42 C revealed the following. (i) The inhibition of ribosomal ribonucleic acid (RNA) synthesis and the block in the conversion of ribosomal RNA precursors to ribosomal RNA which normally occur in infected cells at 37 C was accentuated at 42 C. (ii) The same species of early and late viral messenger RNA were synthesized at 37 and 42 C. (iii) The shift from host cell deoxyribonucleic acid (DNA) synthesis to viral DNA replication occurred earlier at 42 C than at 37 C. These findings indicate that the thermosensitive block(s) in virion formation does not occur at the level of viral DNA replication or transcription of viral mRNA but probably involves the synthesis of late viral proteins or the maturation of the virion.

Adenoviridae↗