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Biomedical subjects

F Rapp

Publications and source records attributed to F Rapp.

At least 325 records · Page 18Linked to original sources

Synthesis of virus deoxyribonucleic acid during abortive infection of simian cells by human adenoviruses.

Rapp, Fred (Baylor University College of Medicine, Houston, Tex.), Lawrence A. Feldman, and Manley Mandel. Synthesis of virus deoxyribonucleic acid during abortive infection of simian cells by human adenoviruses. J. Bacteriol. 92:931-936. 1966.-Inoculation of green monkey kidney cells (GMK) with adenovirus types 2 or 12, under conditions where neither infectious virus was synthesized, resulted in an increase in the uptake of H(3)-thymidine into deoxyribonucleic acid (DNA). Extraction of the DNA from infected cells, followed by identification by isopycnic analysis in CsCl gradients, revealed the presence of virus DNA. Cells infected with adenovirus type 2 yielded DNA giving bands with peak densities of 1.699 g/ml [GMK DNA with 40 moles% guanine + cytosine (GC)] and 1.714 g/ml (adenovirus type 2 DNA with 55 moles% GC). Cells infected with adenovirus type 12 also yielded the GMK DNA and a band at 1.706 g/ml (adenovirus type 12 DNA with 47 moles% GC). The rate of synthesis of adenovirus type 2 DNA in KB cells (productive cycle) and in GMK cells infected only with adenovirus (nonproductive cycle) or with adenovirus and simian virus 40 (adeno-productive cycle) was not significantly different.

Adenoviridae↗

Protection of Measles Virus by Sulfate Ions Against Thermal Inactivation.

Rapp, Fred (Baylor University College of Medicine, Houston, Tex.), Janet S. Butel, and Craig Wallis. Protection of measles virus by sulfate ions against thermal inactivation. J. Bacteriol. 90:132-135. 1965.-The infectivity of measles virus in water is rapidly destroyed at temperatures of 37 C and above. More than 50% of the infectivity is lost after 1 hr at 25 C, and almost 90% loss of infectivity occurs within 24 hr at 4 C. Magnesium chloride enhances the inactivation of the virus at all temperatures tested. Addition of either magnesium or sodium sulfate protects the virus against thermal inactivation. The stabilizing effect is demonstrable at temperatures ranging from 4 to 56 C, but is especially pronounced through 45 C. Prolonged storage (up to 6 weeks) of the virulent virus at 4 C in 1 m magnesium sulfate permits retention of substantial infectivity, whereas storage at 4 C in either water or 1 m magnesium chloride results in a loss of infectivity approximating 99% after 2 weeks. Magnesium chloride also enhances inactivation of the attenuated vaccine strain of measles virus. The attenuated virus, however, is strongly protected by magnesium sulfate against thermal inactivation, and retention of infectivity for long periods of time at 4 C seems feasible when the virus is kept in 1 m magnesium sulfate.

Journal Article↗

Influence of SV40 Genome on the Replication of an Adenovirus-SV40 "Hybrid" Population.

Feldman, L. A. (Baylor University College of Medicine, Houston, Tex.), J. L. Melnick, and F. Rapp. Influence of SV40 genome on the replication of an adenovirus-SV40 "hybrid" population. J. Bacteriol. 90:778-782. 1965.-Replication of a type 7 adenovirus-SV40 hybrid population in primary African green monkey kidney cells was accompanied by the formation of SV40 tumor antigen, adenovirus antigens, and cytopathic changes characteristic of adenovirus infection. Prior infection of the cultures with SV40 stimulated replication of nonintegrated adenovirus 7 but did not enhance the replication of the hybrid virus. These results suggest that the population of the adenovirus-SV40 hybrid studied contains many particles carrying SV40 information. Replication of SV40 virus was not enhanced by co-infection with nonintegrated adenovirus 7 or with the adenovirus-SV40 hybrid. Cytosine arabinoside strongly inhibited replication of the adenovirus-SV40 hybrid population in African green monkey kidney cells. Enhanced replication of nonintegrated adenovirus 7 by SV40 was blocked by cytosine arabinoside; this block could be reversed by 2-deoxycytidine or deoxycytidine triphosphate.

Journal Article↗