Leif Arne Källström
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Featured researches published by Leif Arne Källström.
Journal of Steroid Biochemistry | 1982
Ralph Lennart Brattsand; Arne Thalen; Karin Roempke; Leif Arne Källström; Eva Gruvstad
Abstract The use of topical glucocorticosteroid therapy on large skin areas or in the lung is sometimes restricted by the occurrence of unwanted, general corticoid actions owing to a profound systemic absorption. To decrease this risk potent glucocorticoids with an enhanced ratio between their topical and their systemic glucocorticoid potencies are wanted. Therefore, structure-activity studies were performed in rat models to investigate what influences the type of substitution in the 16α,17α-acetal group and the introduction of fluorine in the 9α- or the 6α,9α-positions have on the topical and the systemic activities, respectively. The introduction of an unsymmetrical 16α,17α-acetal group (named acetal type B) markedly enhanced the topical anti-inflammatory potency compared with that of the conventional 16α,17α-acetonide group (named acetal type A). Both acetal types had a similar systemic glucocorticoid potency, however. 9α-Fluoro and especially 6α,9α-difluoro substitution, on the other hand, enhanced the systemic glucocorticoid activity more than they raised the topical anti-inflammatory potency. Optimal topical to systemic activity ratio was obtained with a nonhalogenated corticoid of acetal type B structure. This compound, budesonide, had at least the same high topical anti-inflammatory potency as fluocinolone acetonide but was about 10 times less potent than this reference to induce systemic glucocorticoid actions. Its lower systemic activity is probably due to a more rapid biotransformation in the liver.
Journal of Steroid Biochemistry | 1982
Paul Andersson; Ralph Lennart Brattsand; Staffan Edsbäcker; Leif Arne Källström; Åke Ryrfeldt
Budesonide is a glucocorticoid of clinical interest for the topical treatment of skin and respiratory diseases. The in vitro liver biotransformation rate and in vivo systemic potency (thymus involution) of budesonide were studied in male and female rats. The biotransformation rate of [3H]-budesonide was about 4 times slower in the female than in the male rat liver 9000 g supernatant (t 1/2; 230 and 57 min, respectively). The systemic potency of budesonide after peroral or subcutaneous administration was higher (by factors of 6 and 2, respectively) in the female than in the male rat. These results suggest that the liver biotransformation rate of budesonide is of great importance in reducing its systemic action in the male rat.
Archive | 1985
Bengt Ingemar Axelsson; Ralph Lennart Brattsand; Carl Magnus Olof Dahlbäck; Leif Arne Källström; Jan William Trofast
Archive | 1987
Bengt Ingemar Axelsson; Ulla Katarina Byström; Carl Magnus Olof Dahlbäck; Leif Arne Källström; Per-Gunnar Nilsson; Jan William Trofast
Archive | 1992
Bengt Ingemar Axelsson; Ralph Lennart Brattsand; Leif Arne Källström; Arne Thalen
Archive | 1998
Bengt Ingemar Axelsson; Leif Arne Källström; Jan William Trofast
Archive | 1987
Bengt Ingemar Axelsson; Ulla Katarina Byström; Carl Magnus Olof Dahlbäck; Leif Arne Källström; Per-Gunnar Nilsson; Jan William Trofast
Archive | 1989
Bengt Ingemar Axelsson; Ulla Katarina Byström; Carl Magnus Olof Dahlbäck; Leif Arne Källström; Per-Gunnar Nilsson; Jan William Trofast
Archive | 1987
Bengt Ingemar Axelsson; Ulla Katarina Byström; Carl Magnus Olof Dahlbäck; Leif Arne Källström; Per-Gunnar Nilsson; Jan William Trofast
Archive | 1987
Bengt Ingemar Axelsson; Ulla Katarina Byström; Carl Magnus Olof Dahlbäck; Leif Arne Källström; Per-Gunnar Nilsson; Jan William Trofast