A rapid nuclear isolation technique was adapted in
order to examine the question of DNA precursor
compartmentation in mammalian cells. By using this method
a reproducible proportion of the cellular nucleotides
remained associated with the isolated nuclei.
Examination, at several different cell densities, of
exponentially growing HeLa cells showed that...
Approximately one quarter of America's students
leave school prior to graduation. Teaching practices
need to be examined if schools are to effectively deal
with the student population. at highest risk of dropping
out. The purpose of this study was to investigate the
attending behaviors high school teachers directed to
students...
Structure-specific synthesis processes are of key importance to the growth of polymorphic functional compounds such as TiO₂, where material properties strongly depend on structure as well as chemistry. The robust growth of the brookite polymorph of TiO₂, a promising photocatalyst, has been difficult in both powder and thin-film forms due...
Investigators have been studying an aggregate
containing enzymes of deoxyribonucleoside triphosphate
biosynthesis in T4-phage infected bacteria. They suggest
that it behaves as an organized complex, efficiently
channeling DNA precursors to the replication apparatus.
Previous work has suggested that about 10 enzyme
activities remain associated through several fractionation
steps. This multi-enzyme...
The ability to faithfully replicate DNA is dependent upon the maintenance
and regulation of its precursors, the deoxyribonucleoside triphosphates.
Enzymes encoded by the bacteriophage T4 have been widely used as models
of biochemical processes. A body of evidence supports the concept that the
bacteriophage T4 enzymes involved in deoxyribonucleotide biosynthesis...
It is well known that the mitochondrial genome has a much higher spontaneous mutation rate than the nuclear genome. mtDNA mutations have been identified in association with many diseases and aging. mtDNA replication continues throughout the cell cycle, even in post-mitotic cells. Therefore, a constant supply of nucleotides is required...
Imbalanced deoxyribonucleoside triphosphate (dNTP) pools are mutagenic for DNA synthesis in both intact cells and cell-free replication systems. Almost certainly, such mutagenesis involves competition between correctly and incorrectly base-paired precursors at replication sites. However, there are certain differences between the intact cell and cell-free systems that do not always allow...
Deoxyribonucleoside triphosphate (dNTP) concentrations measured in cells are not symmetric. dGTP almost always represents only 5-10% of the total dNTP pools in cells. In an in vitro replication system involving semiconservative replication from an SV 40 origin, the mutation frequency of an M13 phagemid replicated by human cell extracts in...
The purpose of this study was to assess reactions to and
opinions about color and color performance by women ages 45 to 54
years. Hypotheses were developed to test relationships and differences
between both perception and acceptance of color change and:
1) the three primary colors, 2) the two methods...
Exposure to polycyclic aromatic hydrocarbons such as benzo[a]pyrene (B[a]P) has been determined to be a risk factor for various forms of human cancer. PAH DNA adducts have been shown to cause mutations, but carcinogenesis is also accompanied by alterations in gene expression. Inhibiting individual cytochrome P450s could clarify the interaction...