Ameloblastoma: report of case.
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Adolescent↗
Biomedical subjects
M R Morrison
Publications and source records attributed to M R Morrison.
Studies on the role of polyamines associated with the ribosomes from Bacillus stearothermophilus.
1. Spermine and spermidine were the main polyamines detectable in Bacillus stearothermophilus. 2. When grown at 65 degrees B. stearothermophilus contained lower concentrations of polyamines per mg. of RNA than when grown at 45 degrees or at 55 degrees . 3. Ribosomes isolated from B. stearothermophilus in 0.01m-tris-hydrochloric acid buffer (pH7.4)-0.01m-magnesium chloride contained sufficient polyamines to neutralize between 4% and 9% of their RNA phosphorus. 4. Removal of polyamines from the ribosomes by dialysis against m-potassium chloride did not appreciably alter the hypochromicity or thermal denaturation profiles of the ribosomes when measured in 0.01m-tris-hydrochloric acid buffer (pH7.4)-0.01m-magnesium chloride, though it did cause a loss of ribosome particles sedimenting at greater than 78s. 5. When ribosomes were dialysed against acridine orange solutions acridine orange bound to the ribosomes and did not displace spermine, but when a mixture of ribosomal RNA and spermine was dialysed against acridine orange the acridine orange displaced the spermine. It is concluded that polyamines in the ribosomes are less accessible for displacement by acridine orange than when polyamines are bound to ribosomal RNA.
Acridines↗
A rapid microprocedure for isolating RNA from multiple samples of human and rat brain.
In order to establish a routine procedure for isolating undegraded RNA from small amounts of rat and human brain tissue, several techniques were investigated. Initial studies demonstrated that undegraded RNA could not be reproducibly isolated from milligram amounts of brain tissue homogenized in an aqueous medium. Several isolation techniques utilizing tissue homogenization in the denaturing agent guanidinium chloride were compared. This method of homogenization, followed by sedimentation of RNA through cesium chloride, resulted in good yields of undegraded translationally active RNA. A maximum of 6 RNA samples could be processed simultaneously. In contrast, when homogenization in guanidinium chloride was followed by repeated guanidinium chloride-ethanol precipitations many samples could be processed simultaneously. The resulting RNA yields were low. The introduction of several modifications in the guanidinium chloride-ethanol precipitation technique resulted in a high yield of undegraded translationally active RNA. DNA was removed by two guanidinium-ethanol precipitations. Residual protein was digested with proteinase K. RNA was precipitated after extraction with phenol-chloroform-isoamyl alcohol. This refined procedure allows the recovery, in high yields, of translationally active undegraded RNA which is both DNA and protein free. Thirty-six samples can be processed in one day.
Animals↗