scholarly journals Basophilia and High Ribonucleic Acid Content of Dividing E. coli Cells

Nature ◽  
1955 ◽  
Vol 176 (4476) ◽  
pp. 310-310 ◽  
Author(s):  
H. E. WADE
Keyword(s):  
Ribonucleic Acid ◽  
Acid Content ◽  
E Coli

scholarly journals The effect of hypermethylation on the functional properties of transfer ribonucleic acid. Formation of aminoacyl-transfer-ribonucleic acid

1969 ◽  
Vol 114 (2) ◽  
pp. 429-435 ◽  
Author(s):  
David J. Pillinger ◽  
John Hay ◽  
Ernest Borek
Keyword(s):  
Amino Acids ◽  
Ribonucleic Acid ◽  
Control Sample ◽  
Transfer Rna ◽  
E Coli ◽  
Functional Sites ◽  
The Individual ◽  
Almost All ◽  
Aminoacyl Transfer ◽  
Kinetics Of

1. The ability of chemically hypermethylated Escherichia coli B transfer RNA to accept 19 amino acids was studied and the results were compared with those obtained with a control sample of E. coli B transfer RNA incubated under similar conditions in the absence of methylating agent. 2. There is a marked decrease in the ability of the modified transfer RNA to accept amino acids in almost all instances. 3. The acceptance of cysteine appears to be unique in that it is enhanced in the hypermethylated transfer RNA. 4. More detailed studies on the kinetics of acceptance for six amino acids is presented, emphasizing the variation in response of the individual amino acids. 5. Increasing hypermethylation causes a progressive decrease in the amino acid acceptance. 6. The results are discussed in terms of methylation at functional sites within the transfer RNA and possible conformational alterations to the structure of the macromolecule.

Changes in the nucleic acid content of the uterus of sheep during involution following ovariectomy and following oestrogenic stimulation

1976 ◽  
Vol 27 (5) ◽  
pp. 669 ◽  
Author(s):  
DA Little ◽  
LJ Lambourne
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Ribonucleic Acid ◽  
Acid Content ◽  
Deoxyribonucleic Acid ◽  
Total Content ◽  
Mean Value ◽  
Nucleic Acid Content ◽  
Uterine Tissue ◽  
Rna Concentration

The concentrations of nucleic acids, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), in ovine uterine tissue were studied to determine whether the ratio RNA/DNA might be used in the bioassay of oestrogenic activity. As the uterus decreased in size with time after ovariectomy, the concentration of DNA increased markedly, but the total content of DNA in the uterus remained constant (mean value 342 ? 8 (SE) mg). The RNA concentration of the tissue decreased during involution, with the result that a highly significant reduction of 33% in the RNA/DNA ratio occurred within 2 weeks of ovariectomy. The ratio decreased further with time. Other ewes were treated for 3 days with diethylstilboestrol dipropionate (10 µg/day), commencing 2 weeks after ovariectomy; the stage of the oestrous cycle at which the ovaries were removed had no effect on the response to the oestrogen. Changes in the nucleic acid concentrations in the uteri of these ewes, and the results obtained during involution, indicate that the RNA/DNA ratio of uterine tissue in ovariectomized ewes has potential as a basis for the bioassay of materials of low oestrogenic potency.

scholarly journals The ribonucleic acid content of some mammalian erythrocytes

1955 ◽  
Vol 53 (2-3-4) ◽  
pp. 499-501
Author(s):  
Helion Povoa Jr.
Keyword(s):  
Guinea Pig ◽  
Red Blood Cells ◽  
Ribonucleic Acid ◽  
Acid Content ◽  
Blood Cells

RNA was determined in red blood cells of man and other mammals. Our report is based on 41 determinations. Red blood cells of rat showed the highest values in comparison with the blood cells of guinea pig, rabbit, horse and sheep which showed the lowest values, and man with intermediate ones. The method used was a combination of Schimidt and Thanhauser and Schneider extractions with the final reactions of pentose with the orcinol reagent colorimetrically measured.

scholarly journals The bar-properties, in particular glucosylation of deoxy-ribonucleic acid, in crosses of bacteriophages T2 and T4

1967 ◽  
Vol 9 (2) ◽  
pp. 149-158 ◽  
Author(s):  
B. de Groot
Keyword(s):  
Protective Effect ◽  
Host Range ◽  
Ribonucleic Acid ◽  
Bacteriophage T4 ◽  
The Other ◽  
New Host ◽  
E Coli ◽  
Marker Rescue ◽  
Single Burst

Analysis of the inheritance of the three bar-properties of bacteriophage T4: exclusion of T2 from the progeny of crosses, glucosylation of the hydroxymethylcytosine (HMC)moiety of the DNA according to T4, and plating with large plaques on E. coli K strains, was carried out by means of marker rescue from T4 by T2 on E. coli K (λh) as a selective indicator. Five of the strains isolated plated with large plaques on K (λh), but did not exclude T2 and showed T2 glucosylation; plating on E. coli K (λh) was found to segregate from the other two bar-properties. The sixth isolate showed, in addition to plating with large plaques on K, partial non-excludability by the parental T4 and T4 glucosylation of HMC. If partial non-excludability is the result of T4 glucosylation, the role of the additional glucose substitutions might be a protective effect on the DNA against the exclusion factor of T4. This proposal is supported by the analysis of the progeny from a single burst from a cross of T4 and T2. The following T2 genes were partially excluded: host-range, no exclusion of parental T2, sensitivity to ultraviolet, and limited plating efficiency on E. coli K (λh). The exclusion factor of T4 is not transmitted to all progeny and does not behave like a bar-property. Only resistance to exclusion and T4 glucosylation were transmitted to all twenty-seven progeny of the single burst. The elimination of sensitivity to exclusion and T2 glucosylation is explained by assuming that the recombinant class with the exclusion factor of T4 and T2 α-glucosylation will exclude itself and be suicidal upon infection of a new host. Exclusion and differential glucosylation are discussed with regard to restriction and modification, respectively.

THE EFFECT OF LARGE DOSES OF THIOUREA ON THE COMPOSITION OF THE LIVER AND URINE OF RATS

1956 ◽  
Vol 13 (2) ◽  
pp. 141-149 ◽  
Author(s):  
F. DOLJANSKI ◽  
Z. ESHKOL ◽  
D. GIVOL ◽  
E. KAUFMANN ◽  
E. MARGOLIASH
Keyword(s):  
Uric Acid ◽  
Urinary Excretion ◽  
Ribonucleic Acid ◽  
Acid Content ◽  
Catalase Activity ◽  
Deoxyribonucleic Acid ◽  
Liver Weight ◽  
Liver Glycogen ◽  
Chemical Changes ◽  
Thiourea Treatment

SUMMARY Following the observation that large daily doses of thiourea induced numerous mitoses in the liver of rats [Rachmilewitz, Rosin & Doljanski, 1950], the concomitant chemical changes in the liver and urine of thiourea-treated rats were investigated. It was found that: (1) The mitogenetic reaction, which occurred on the 3rd day of treatment with the drug, was preceded by (a) a decrease in liver catalase activity to 30–50% of the normal within 12 hr; (b) an increase in total liver weight and concentration of liver ribonucleic acid within 2 days. The enlarged liver was normal with respect to protein, lipid, water and deoxyribonucleic acid content. (2) The concentration of liver glycogen decreased markedly on the 1st day of thiourea treatment but returned to normal by the 2nd or 3rd day. (3) During the period of treatment with thiourea there was an increase in the urinary excretion of uric acid, allantoin, and phosphate, as well as glucosuria and polyuria. There was no change in the excretion of urea and total sulphate. (4) All these changes, both in the liver and the urine, were fully reversible on withdrawing the drug.

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