Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038187 (starvation)
 24,951 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

When the excision proficient strain E. coli WP2 Hcr+ trp- was grown to stationary phase by glucose starvation in M-9 minimal medium before UV -irradiation, the ability of nutrient broth enrichment of minimal medium to enhance trp- leads to Trp+ reversion was greatly reduced. Less than 50% of the Trp+ revertants were found to be ochre suppressors. However, in the WWP2 Hcr- strain, 75-86% of the tested revertants were ochre suppressors. This indicates that, under the cultural conditions employed, many potential suppressor mutations were removed by excision repair in the presence of broth enrichment. Broth enhancement of reversion also occurred in the Hcr- strain, which indicates that a less error-prone mode of recombination repair functions under minimal growth conditions. An Hcr+ strr derivative of WP2 Hcr+ was more resistant than its strs parent to the lethal effect of UV light and showed a lower UV-induced Trp+ reversion frequency. The percentage of Trp+ revertants that were due to ochre suppressors was markedly reduced in the strr strain. The Hcr- strr strain also had a lower UV-induced Trp+ reversion frequency than its strs parent. The excision repair inhibitor caffeine had little effect at lower UV doses on increasing Trp+ reversion in both Hcr+ strains. Acriflavine, however, was effective at lower UV doses in enhancing reversiin of the Hcr+ strains and the degree of enhancement increased with the dose. Acriflavine appeared to specifically enhance the number of ochre suppressing Trp+ revertants. In both Hcr- strains (strs and strr) caffeine (500 mug/ml) had no effect on survival but reduced the UV-induced Trp+ reversion frequency acting as an antimutagen. In contrast, acriflavine (2 mug/ml) decreased survival and increased the Trp+ reversion frequency of the Hcr- strains. The data on spontaneous Trp+ reversion frequencies show that the Hcr+ strs strain had a higher spontaneous reversion frequency than the Hcr- strs strain on all plating media. Further, caffeine was shown to reduce spontaneous Trp+ reversion in both Hcr+ and Hcr- strains while acriflavine increased the spontaneous reversion frequencies of both strains.
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PMID:The effect of streptomycin resistance, caffeine and acriflavine on ultraviolet light-induced reversion to tryptophan independence in strains of Escherichia coli B/r. 110 29

Acriflavine uptake and resistance were investigated in red, sensitive Serratia marcescens cells and in orange, resistant mutant cells and their respective spheroplasts. Acriflavine-sensitive cells bound more acriflavine than acriflavine-resistant cells. Spheroplasts from sensitive and resistant cells were both resistant to and bound similar amounts of acriflavine. Sensitive cells were resistant to acriflavine in medium supplemented with 0.01 M MgSO(4) and 0.5 M sucrose. In the presence of 0.01 M MgSO(4) and 0.5 M sucrose, acriflavine binding by sensitive cells was reduced to the level of binding by resistant cells. Inhibition of metabolism by carbon starvation, chloramphenicol, As(2)O(3), nitrosoguanidine, and bromouracil did not affect the uptake of acriflavine by sensitive and resistant cells. Rapid temperature changes did not alter the acriflavine-binding capacity of the cells, and no temperature dependence of acriflavine uptake or release was observed at 0 and 30 C. Acriflavine uptake by both sensitive and resistant cells increased with increase in pH from 5.7 to 8.0. The logarithm of acriflavine uptake was a linear function of the logarithm of the acriflavine concentration in the binding medium.
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PMID:Acriflavine uptake and resistance in Serratia marcescens cells and spheroplasts. 457 26