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Biomedical subjects

M Ledoux

Publications and source records attributed to M Ledoux.

79 records · Page 5Linked to original sources
PubMed1972

Distribution of pyrimidine oligonucleotides in strands L and H of Bacillus subtilis DNA.

The distribution of pyrimidine oligodeoxynucleotide clusters in L and H strands of Bacillus subtilis DNA separated by methylated albumin-Kieselguhr has been determined. Preparations of native and single-stranded DNA were degraded with diphenylamine in formic acid, and the released isostichs with the general formula of Py(n)P(n+1) were separated on DEAE-cellulose by chain length. Eleven isostichs were obtained for strands L and H in unequal proportions. Each isostich fraction was subfractionated by base composition on DEAE-cellulose at pH 3.0. 61 Pyrimidine oligonucleotide clusters were separated from the H strand and only 46 from the L strand. The findings show a higher degree of asymmetry between the strands in the distribution of cytosine-rich clusters as compared with thymine-rich clusters. The longest cytosine oligodeoxynucleotide present in both strands is of chain length 5. There is an unusually high distribution of thymine oligodeoxynucleotides of length 5-11. Up to chain length 6, the distribution of thymine oligodeoxynucleotides between the strands is about equal; from chain length 7 to 11 they occur predominantly in the H strand.

Amines↗
PubMedDate not supplied

Plasma catecholamines at rest and exercise in subjects with high- and low-trait anxiety.

The purpose of this study was to compare the plasma catecholamine concentration at rest and in response to exercise in subjects with low and high trait anxiety (TA). Six subjects with low TA and six subjects with high TA were selected among 149 males college students on the basis of their results on three TA tests (STAI, IPAT, 16 PF). Plasma norepinephrine (NE) and epinephrine (E) concentrations (pg/ml) were measured at rest in supine position and during mild and moderate exercises of 5 min duration (about 40% and 60% of the individual VO2max) on bicycle ergometer. Plasma E concentrations at rest and exercise were not significantly different in subjects with low (33 +/- 6, 82 +/- 11, and 197 +/- 49) or high TA (41 +/- 7, 62 +/- 13, and 229 +/- 52). Plasma NE concentration was not significantly different at rest and in response to mild exercise in low (235 +/- 52; 666 +/- 64) and high-TA subjects (223 +/- 36; 610 +/- 88) but was significantly higher in high-TA than in low-TA subjects in response to moderate exercise (2510 +/- 618 vs. 1243 +/- 234). These results show 1) that plasma NE and E concentrations at rest and in response to light exercise are similar in low- and high-TA subjects, and 2) that subjects with high TA have a greater plasma NE response to the psychologic stress and/or to the homeostatic challenge of moderate exercise.

Adolescent↗