1. The purpura-producing principle of Pneumococcus is non-antigenic in the sense that it does not stimulate the formation of antibodies. 2. White mice acquire an increased resistance to purpura as a result of repeated injections of toxic doses of the purpura substance. 3. The serum of rabbits immunized with the purified purpura principle, with "S" and "R" strains of Pneumococcus or with cell ex...

Evidence in support of a novel lyssavirus was obtained from brain samples of an African civet in Tanzania. Results of phylogenetic analysis of nucleoprotein gene sequences from representative Lyssavirus species and this novel lyssavirus provided strong empirical evidence that this is a new lyssavirus species, designated Ikoma lyssavirus.

Ionic and nonionic interactions between the adenoviral histone-like proteins and DNA were examined by determining effects of ionic strength and urea concentration on disruption of viral nucleoprotein. The viral proteins were as susceptible to dissociation by salt in the presence of urea as histones. Nonionic interactions between viral proteins appeared more extensive than those between histones.

We report the first genetic characterization of wildtype measles viruses from Uganda. Thirty-six virus isolates from outbreaks in 6 districts were analyzed from 2000 to 2002. Analyses of sequences of the nucleoprotein (N) and hemagglutinin (H) genes showed that the Ugandan isolates were all closely related, and phylogenetic analysis indicated that these viruses were members of a unique group wi...

In recent years, the number of human rabies cases in the People's Republic of China has increased during severe epidemics in 3 southern provinces (Guizhou, Guangxi, and Hunan). To analyze the causes of the high incidence of human rabies in this region, during 2005-2007, we collected 2,887 brain specimens from apparently healthy domestic dogs used for meat consumption in restaurants, 4 specimens...

John Maynard Smith compared protein evolution to the game where one word is converted into another a single letter at a time, with the constraint that all intermediates are words: WORD→WORE→GORE→GONE→GENE. In this analogy, epistasis constrains evolution, with some mutations tolerated only after the occurrence of others. To test whether epistasis similarly constrains actual protein evolution, we...

Rad54 and Rad51 are important proteins for the repair of double-stranded DNA breaks by homologous recombination in eukaryotes. As previously shown, Rad51 protein forms nucleoprotein filaments on single-stranded DNA, and Rad54 protein directly interacts with such filaments to enhance synapsis, the homologous pairing with a double-stranded DNA partner. Here we demonstrate that Saccharomyces cerev...

The fractionation of deoxypentose nucleic acids, recently reported from this laboratory (1, 2), is essentially based on the fractional extraction of nucleohistone or artificial histone nucleates with salt solutions of increasing concentration in the presence of a chloroform phase. In this manner, a series of fractions of regularly graded composition (falling proportions of guanine and cytosine,...