A biosystematic study of Coreopsis saxicola (Compositae)

On the basis of morphological, hybridization, genetic, and field studies, it is proposed thatCoreopsis saxicola Alex. be reduced to varietal rank asC. grandiflora var. saxicola.     

Passive Electrical Properties of Microorganisms: V. Low-Frequency Dielectric Dispersion of Bacteria

Very high dielectric constants have been observed for bacteria at low frequencies. High dielectric constants such as these can be explained by a theory which has been developed for the low-frequency dielectric dispersion of porous charged particles and which has been tested successfully through measurements with ion exchange resins. The bacterial cell wall is electrically similar to an ion exchange resin. Observations show that the theory provides a quantitative explanation for the low-frequency dielectric dispersion of bacteria.     

The Relationship between Cell Membrane Potassium Ion Transport and Glycolysis : The effect of ethacrynic acid

Cell membrane transport of K⁺ stimulates the rate of glycolysis in Ehrlich ascites tumor cells. A study of the characteristics of this relationship indicates that the stimulation occurs under anaerobic as well as under aerobic conditions. The data suggest that glycolysis is stimulated by a K⁺ transport mechanism that is coupled to Na⁺ transport because the effect is blunted or abolished when the principal intracellular ion is lithium or choline. This stimulus to glycolysis is blocked by ouabain and ethacrynic acid, agents that have been shown to inhibit monovalent cation transport in erythrocytes. In contrast to the action of ouabain, glycolysis is inhibited by ethacrynic acid in Ehrlich ascites tumor cells in the absence of cell membrane K⁺ transport. In studies with ghost-free hemolysates of human erythrocytes and with cytosol prepared from Ehrlich ascites tumor cells, ethacrynic acid significantly blocks lactate formation from fructose diphosphate demonstrating the direct inhibitory effect of this agent on one or more enzymes of the Embden-Meyerhof pathway. Since ethacrynic acid has no influence on lactate formation in intact erythrocytes utilizing an endogenous substrate, the presumptive site of inhibition is proximal to the 3-phosphoglycerate level.     

Electrophoretic separation of multiple bands with beta-glucuronidase activity in human sera

An electrophoretic procedure is described which resulted in the separation of up to four bands with beta-glucuronidase activity in human sera. Initial screening of a small sample of individuals revealed persons with two, three, and four bands.Supported by Special Project Grant Number 414 of the Children's Bureau, U.S. Department of Health, Education and Welfare.     

Serological Comparison of the Three Morphological Phases of Coccidioides immitis by the Agar Gel Diffusion Method

Hyperimmune sera against spherules and against arthrospores of Coccidioides immitis were prepared by inoculation of rabbits. The antibody content of these sera was studied by the agar gel diffusion method. It was observed that antispherule pooled sera formed multiple precipitin bands with extracts of spherules and of arthrospores. The antiarthrospore pooled serum, however, failed to precipitate with the spherule extract, and formed a single band in the presence of an arthrospore solution. When the spherule and the arthrospore extracts were tested with a variety of different antisera, it was observed that the spherule preparation formed bands only in combination with anti-purified spherule pooled serum, whereas the arthrospore extract precipitated with anti-purified spherule, antiarthrospore, and anti-Histoplasma capsulatum pooled sera. It was also observed that a spherule culture supernatant solution formed five precipitin bands in combination with anti-spherule pooled sera, formed one band with pooled antiserum from rabbits with coccidioidomycosis, and did not precipitate in the presence of antiarthrospore pooled serum. Coccidioidin, however, formed two bands in the presence of any of these antisera. It was therefore concluded that extracts from the spherule phase of C. immitis differed from solutions obtained from the arthrospore and mycelial phases.     

Comparison of the requirements for ribonucleic acid synthesis with the requirements for deoxyribonucleic acid synthesis in animal tissues

Ribonucleic acid polymerase and deoxyribonucleic acid polymerase have been partially purified from bovine lymphosarcoma, lymph node, and thymus. An examination of the deoxyribonucleic acid requirements of the two enzymes indicates that “native” deoxyribonucleic acid is the preferred template for ribonucleic acid synthesis; heat-denatured deoxyribonucleic acid is considerably less active. The primer requirements for deoxyribonucleic acid synthesis differ: “native” deoxyribonucleic acid is usually inactive, while denatured deoxyribonucleic acid is active. The two enzymes also differ in pH optima and in their requirements for metal cofactors.     

Serology of Rubella—Comparison of Fluorescent Antibody,Complement Fixation and Neutralization Tests for Diagnosis of Current Infections and Determination of Sero-immunity

Neutralization, complement fixation (CF) and indirect fluorescent antibody (FA) assays for rubella virus were compared for sensitivity in the serologic diagnosis of infection, for demonstrating antibody in the sera of infants with suspected rubella syndrome, and in the detection of antibody elicited by past infection (determination of immunity status). The combination of CF and FA tests was shown to be the most useful for serologic diagnosis of infection, largely eliminating the need for the slower and more cumbersome interference neutralization test.Neutralizing antibodies were found to appear rapidly in the course of infection, antibodies demonstrable by immunofluorescent staining appeared slightly later, and CF antibodies were rarely demonstrable in sera collected earlier than 14 days after onset of illness. Antibodies detected by all three techniques showed good correlation in infants with clinical evidence of rubella syndrome and corresponding maternal sera. The indirect FA technique compared favorably with the neutralization test for the detection of antibody elicited by past infection (determination of immunity status) and offered distinct advantages in ease of technical performance and more rapid results. In both current and past infections, FA titers tended to be higher than neutralizing antibody titers.