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C WALLIS

Publications and source records attributed to C WALLIS.

At least 19 recordsLinked to original sources
PubMed1965

PHOTODYNAMIC INACTIVATION OF ENTEROVIRUSES.

Wallis, Craig (Baylor University College of Medicine, Houston, Tex.), and Joseph L. Melnick. Photodynamic inactivation of enteroviruses. J. Bacteriol. 89:41-46. 1965.-Enteroviruses are usually resistant to photodynamic inactivation, but they can be rendered completely photosensitive to proflavine at pH 9 to 10, if they are first purified by filtration through an anion resin. In addition, if enteroviruses are grown in cells maintained in a salt-glucose medium, they can be photosensitized. Of 38 enteroviruses tested, 10 were rendered completely photosensitive to proflavine, or toluidine blue, or both, and the remaining 28 viruses were sensitized, but to a lesser degree. The binding of dye to the virus can be reversed by lowering the pH.

Aniline Compounds↗
PubMed1965

DIFFERENCES IN CYSTINE DEPENDENCE AND CHROMATOGRAPHIC BEHAVIOR BETWEEN TWO TYPE 4 ECHOVIRUS STRAINS.

Wallis, Craig (Baylor University College of Medicine, Houston, Tex.), and Joseph L. Melnick. Differences in cystine dependence and chromatographic behavior between two type 4 echovirus strains. J. Bacteriol. 89:1310-1313. 1965.-Type 4 strains of echovirus, which are known to differ in the ease in which they can be neutralized, have been found to differ in other properties also. The prototype strain (Pesascek) differed from a readily neutralizable strain (DuToit) in that the Pesascek strain could be stabilized by cystine to thermal inactivation. Furthermore, the prototype virus required cyst(e)ine for growth under agar, whereas the DuToit strain was not affected. The viruses also reacted differently on anion-exchange resins. Pesascek virus had surface groups capable of exchanging for phosphate ions and, thus, was readily adsorbed, whereas DuToit virus was not bound by the resins under the same conditions. Only a small fraction of Pesascek virus was found to pass through the resin column. This fraction bred true, in that it yielded progeny that behaved like DuToit in not exchanging for phosphate. However, in neutralization tests, the progeny of this fraction retained the immunological property of the parent Pesascek virus.

Adsorption↗
PubMed1963

THERMOSENSITIVITY OF POLIOVIRUS.

Wallis, Craig (Baylor University College of Medicine, Houston, Tex.) and Joseph L. Melnick. Thermosensitivity of poliovirus. J. Bacteriol. 86:499-504. 1963.-Polioviruses are thermosensitive agents, although thermoresistant strains have been obtained and reported in the literature. Such resistant strains can be developed by exposure of the virus to cystine during multiple-cycle yields. Thermoresistant strains can be converted to the thermosensitive state by passing the virus in cells maintained in a cystine-free medium, or by reducing the virus with glutathione. The thermoresistant variants seem to result from the conditions under which virus is grown and harvested. Consequently, many such thermostable polioviruses actually represent phenotypic rather than genotypic variation.

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