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Biomedical subjects

A Howard

Publications and source records attributed to A Howard.

At least 127 records · Page 7Linked to original sources
PubMed1975

A study of abrupt lithium withdrawal.

Twelve patients were abruptly switched from lithium to placebo as part of a double-blind cross-over study. In contrast to other drugs effective in mood disorders, lithium produced no withdrawal syndrome.

Adolescent↗
PubMed1975

Chromosomes and cellular radiosensitivity. IV. A new radiotaxon represented by the ferns.

Survival curves were constructed and D0 values determined after X-irradiation of single-celled germinating spores of 14 species of ferns, which had a wide variation in interphase chromosome and nuclear volumes and in DNA content per chromosome and per nucleus. A good fit to a line of slope equal to -1 is given on a log-log plot relating D0 to interphase chromosome volume. In a previous publication (Sparrow, Underbrink and Sparrow 1967), ferns fell into radiotaxon VIII, but the new data suggest that they should be assigned to a new group (VIIa) falling midway between radiotaxa VII and VIII. The calculated energy absorption per chromosome at D0 for VIIa is also intermediate between those for VII and VIII. If the value of this parameter is set at 1 for radiotaxon V, that for VIIa is approximately 32 times greater and the radiotaxa V, VI, VII and VIIa form a series 1 : 4 : 14 : 32. The new results indicate that radiotaxon VIII may have to be abandoned unless some other radiobiologically unexplored group (e.g. algae) fills the gap.

Cell Survival↗